A protein array was fabricated for a miniaturized immunoassay using microcontact printing ($mu$CP). A polydimethylsiloxane (PDMS) stamp with a 5 $mu$m$ imes$5 /$mu$m dimension was molded from a silicon master developed by photolithography. Under optimal fabrication conditions, including the baking, incubation, and exposure time, a silicon master was successfully fabricated with a definite aspect ratio. An antibody fragment was utilized as the ink for the $mu$CP, and transferred to an Au substrate because of the Au-thiol (-SH) interaction. The immobilization and antibody-antigen interaction were investigated with fluorescence microscopy. When human serum albumin (HSA) was applied to the protein array fabricated with an antibody against HSA, the detection limit was 100 pg/ml of HSA when using a secondary antibody labeled with a fluorescence tag. The fabricated protein array maintained its activity for 14 days.