To generate an image signal from electromagnetic waves in a plurality of wavelength bands with one image pick-up device.

Infrared rays and visible rays are successively extracted by a chopper 10 and are converted into image signals by an image pick-up element 12. A timing signal is generated by a timing generation part 19 from the position information of the chopper 10 detected by a sensor 14 and the image signals of visible rays or infrared rays are extracted and outputted from a signal outputted from the image pick-up element 12 in synchronization with the signal by an extraction part 13a.