To provide an imaging device for reducing the deterioration of picture quality due to the rays of light reflected and absorbed in a non-imaging area between imaging elements in the case of arranging a plurality of imaging elements to acquire and observe an image.

This imaging device (1) is configured to illuminate an object (225) with the rays of light from a light source (110) by an illumination optical system (100), and to acquire the image of the object via an imaging optical system (300) by using a plurality of imaging elements (430). This illumination optical system includes a plurality of integrators (121), and at least one of the plurality of imaging elements is illuminated with the rays of light outgoing from one of those integrators, and at least one of imaging elements other than the imaging element which is illuminated with the rays of light outgoing from one integrator among the plurality of imaging elements is illuminated with the rays of light outgoing from the residual integrators.