PURPOSE: To reduce a thermal stress, which is generated when a hybrid type infrared detecting element is cooled at an operating temperature and is generated in a photodiode part and an epitaxial interface, and to improve the bonding strength of bumps.

CONSTITUTION: As a polysilicon bump 10 doped in a high concentration and an In thin film are used for bump bondings, the bonding strength and electrical conductivity of bumps are high. Moreover, as the flexibility of the bump 10 is low and the thickness of an Si IC 9 is equal with that of an Si substrate 14, a warpage is not generated in a hybrid type infrared detecting element at the time of of cooling of → the hybrid type infrared detecting element. At this time, a thermal stress of the largest thermal stress part 4 is the force of the elastic limit of a CdTe buffer layer 18 and a thermal stress in a photodiode 5 is the degree of half of the force of the elastic limit of an HgCdFe layer. A reinforcing polysilicon bump 12 and a CdTe bump 8 formed on the endmost part of the HgCdTe layer 7 prevent the generation of a local breakdown of the crystal of a photodiode 16 formed at the endmost of an array. Thereby, the highly reliable infrared detecting element can be manufactured at a high yield to a cooling cycle.