-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 KeO+r7Hi3KgMawWKJQI8ow==

<SEC-DOCUMENT>0001261711-04-000003.txt : 20040102
<SEC-HEADER>0001261711-04-000003.hdr.sgml : 20040101
<ACCEPTANCE-DATETIME>20040102175612
ACCESSION NUMBER:		0001261711-04-000003
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040101
FILED AS OF DATE:		20040102

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BRENNER NATHANIEL
		CENTRAL INDEX KEY:			0001261711

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-13470
		FILM NUMBER:		04501751

	MAIL ADDRESS:	
		STREET 1:		1 LOS GATOS
		CITY:			IRVEINE
		STATE:			CA
		ZIP:			92612

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NANOMETRICS INC
		CENTRAL INDEX KEY:			0000704532
		STANDARD INDUSTRIAL CLASSIFICATION:	MEASURING & CONTROLLING DEVICES, NEC [3829]
		IRS NUMBER:				942276314
		STATE OF INCORPORATION:			CA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1550 BUCKEYE DRIVE
		CITY:			MILPITAS
		STATE:			CA
		ZIP:			95035
		BUSINESS PHONE:		408-435-9600

	MAIL ADDRESS:	
		STREET 1:		1550 BUCKEYE DRIVE
		CITY:			MILPITAS
		STATE:			CA
		ZIP:			95035
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2004-01-01</periodOfReport>

    <dateOfOriginalSubmission>2004-01-02</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000704532</issuerCik>
        <issuerName>NANOMETRICS INC</issuerName>
        <issuerTradingSymbol>NANO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001261711</rptOwnerCik>
            <rptOwnerName>BRENNER NATHANIEL</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1 LOS GATOS</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>IRVEINE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92612</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>

        <derivativeTransaction>
            <securityTitle>
                <value>NANOMETRICS,  common</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>14.71</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-01-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>14.71</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2005-01-01</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2009-01-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Nanometrics, common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>50000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>

    </derivativeTable>

    <footnotes>
        <footnote id="F1">These options become excercisable per schedule: 33 1/3 % after 1 year,33 1/3 %aftersecond year, 33 1/3 % after third year following grant date.</footnote>
    </footnotes>

    <remarks>This revision replaces Form 4 incorrectly filed earlier on 01/02/2004</remarks>

    <ownerSignature>
        <signatureName>Nathaniel Brenner</signatureName>
        <signatureDate>2004-01-02</signatureDate>
    </ownerSignature>

</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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