PURPOSE: To enhance the yield, reproducibility and device performance while abating the noise by a method wherein a lower electrode of an infrared ray detector is formed on a supporting substrate so as to be partly in contact with an electrode pattern formed on the substrate surface.

CONSTITUTION: A J-FET and an integrated circuit are formed on a P-Si substrate 11 while a source electrode 13 and a gate electrode 14 of the J-FET are provided. Next, a heat absorbent film 15 serving both as an lower electrode is formed using the photoetching step and the evaporating technology in the specified position on an insulating film 12 on the P-Si substrate surface. Next, a thin film to be an infrared ray detector 16 is formed using the coating technology furthermore, another heat absorbent film 17 to be the upper electrode is deposited using the evaporating technology. Later, the heat absorbent film 17 and the infrared ray detector 16 are patterned by the dry-etching technology using a photoresist film formed in the specified shape and position by the photoetching step as a mask so as to remove the photoresist film.