EXHIBIT 21

AFFYMETRIX, INC.

LIST OF SUBSIDIARIES

Affymetrix Biotech Ltda., a wholly-owned subsidiary incorporated in Brazil and doing business under such name.

Affymetrix Biotech Shanghai Ltd., a wholly-owned subsidiary incorporated in China and doing business under such name.

Affymetrix France S.A.S., a wholly-owned subsidiary incorporated in France and doing business under such name.

Affymetrix GmbH, a wholly-owned subsidiary incorporated in Germany and doing business under such name.

Affymetrix Japan K.K., a wholly-owned subsidiary incorporated in Japan and doing business under such name.

Affymetrix Pte Ltd, a wholly-owned subsidiary incorporated in Singapore and doing business under such name.

Affymetrix, UK Ltd, a wholly-owned subsidiary incorporated in the United Kingdom and doing business under such name.

Bender MedSystems GmbH, a wholly-owned subsidiary incorporated in Austria and doing business under such name.

Bender MedSystems Inc. a wholly-owned subsidiary incorporated in California and doing business under such name.

eBioscience GmbH, a wholly-owned subsidiary incorporated in Germany and doing business under such name.

eBioscience, Inc., a wholly-owned subsidiary incorporated in California and doing business under such name.

eBioscience, Ltd., a wholly-owned subsidiary incorporated in the United Kingdom and doing business under such name.

eBioscience SAS, a wholly-owned subsidiary incorporated in France and doing business under such name.

Natutec GmbH, a wholly-owned subsidiary incorporated in Germany and doing business under such name.

Panomics, L.L.C., a wholly-owned subsidiary incorporated in California and doing business under such name.

Panomics SRL, a wholly-owned subsidiary incorporated in Italy and doing business under such name.

Powder Detergents, Inc., a wholly-owned subsidiary incorporated in Ohio and doing business under such name.

USB Corporation, a wholly-owned subsidiary incorporated in Ohio and doing business under such name.