Cover Page - shares	6 Months Ended
	Jul. 01, 2023	Jul. 31, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Entity Interactive Data Current	Yes
Document Period End Date	Jul. 01, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Document Quarterly Report	true
Document Transition Report	false
Entity Registrant Name	INTEVAC, INC.
Entity Central Index Key	0001001902
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Trading Symbol	IVAC
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity File Number	0-26946
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	94-3125814
Entity Address, Address Line One	3560 Bassett Street
Entity Address, City or Town	Santa Clara
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	95054
City Area Code	408
Local Phone Number	986-9888
Entity Small Business	true
Title of 12(b) Security	Common Stock
Entity Common Stock, Shares Outstanding		26,302,666
Security Exchange Name	NASDAQ