Exhibit 23.1

              CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS

We consent to the reference to our firm under the caption "Experts" in the
Registration Statement (Form S-3) of Affymetrix, Inc. for the registration of
1,285,237 shares of its Common Stock and to the incorporation by reference
therein of our report dated February 8, 2000, except for the third paragraph
of Note 1 and Note 13 as to which the date is February 9, 2000, with respect
to the consolidated financial statements of Affymetrix, Inc. included in its
Current Report on Form 8-K dated April 7, 2000, filed with the Securities and
Exchange Commission.


                                                        /s/ Ernst & Young LLP

Palo Alto, California
December 14, 2000