PURPOSE: To provide the infrared image pickup device which observes infrared images having too kinds of wavelength band by one image pickup device.

CONSTITUTION: An infrared detector 1 having two detecting elements 11 and 12 which detect two kinds of infrared wavelength band component respectively, two infrared filters 24a and 24b one of which is temporarily inserted to an optical scanning system 2 to limit wavelength band components of infrared rays made incident on the infrared detector 1 to one of two kinds of infrared wavelength band component, and a television monitor 4 on which the video signal outputted from a video circuit 33 is displayed are provided as one body. Two infrared filters 24a and 24b are switched to pick up the infrared images having two kinds of wavelength band by one device.