A microwave oven (MWO) of National brand was applied for Labeled Streptavidin Biotin immunohistochemical staining (LSAB method) on autopsy materials of 20 cases to detect 10 kinds of antigen of heart and brain: The keys to manipulate MWO as follows: (1) Recovery of antigen: submerge sections in 0.01M citrate buffer (pH 6.0), turn MWO to the position of DEF (210W) for 10 min, reaching temperature 92 degrees C-98 degrees C. (2) add normal serum, first antibody, second biotinylated antibody and streptavidin complex, then turn MWO to the position of LOW (70W) for 5 min, reaching temperature 20 degrees C-37 degrees C. Other steps were the same as the standards. Results showed: MWO can recover the destroyed or covered antigen, improve positive staining degree, reduce background's stain and shorten staining time.