PURPOSE: To obtain an infrared ray image pickup device which has high performance by opposing infrared ray detecting element group made of compound semiconductor and CCD made of Si, coupling them via metal projections and electrically and optically independently isolating between an organic resin layer and the elements.

CONSTITUTION: An N+ type InSb film 22 is formed by a liquid phase epitaxially growing method on (111) plane of a mirror-finished P type InSb surface 21 as an infrared ray receiving side. The substrate 21 is polished to a thickness of approx. 50μm, mesa etched in the prescribed pattern, and an anodically oxidized film is covered. Then, resin 23 is rotatably coated to bury the mesa groove and to solidify the resin, and the layer 23 is polished until the layer 21 is exposed. Low melting point solder projections 24 containing mainly In are formed only on the exposed P type layer, and fusion-bonded to the input diode 26 of the CCD element 25 of Si. Then, the layer 22 side is chemically etched to expose the layer 23, and the N+ type layer and hence the photodetector 27 of the infrared ray detecting element is completely individually isolated via the resin 23. According to this configuration, the image pickup device which has excellent mechanical strength and high reliability can be obtained.