Pyroelectric-type infrared receiving element and infrared sensor utilizing the same

A pyroelectric-type IR receiving element (1) comprises a pyroelectric substrate (10) which is fixed to a supporting body at its support ends (16), and at least one rectangular patch (11,12,13,14) formed in the substrate. The patch is formed on its opposite surfaces with first and second electrodes (20,21) which are overlapped to each other. The substrate has a U-shaped slit (30) composed of a pair of side slits (31) and a base slit (32) connecting the side slits. The U-shaped slit surrounds continuously three sides of the patch, so that the patch is supported by the substrate in a cantilever fashion at a cantilever end which is opposed to one of the support ends of the substrate. Since a thermal stress applied to the substrate when the substrate is exposed to a temperature change is absorbed by the U-shaped slit, a stress concentration to be considered is not developed in the patch. As a result, it is possible to reduce the occurrence of popcorn noise, while maintaining good IR sensitivity.