An imaging device includes a light source capable of emitting multi-types of illumination light beams, an imaging unit including an imaging element driven by a rolling shutter method, a light source control unit, a frame image control unit, and an image generation unit. The frame image control unit controls the light source control unit and the imaging unit so as to obtain an output having a frame group, in which second exposure frames Exp2 and Exp4 are respectively disposed before and after a first exposure frame Exp3, as one period. The imaging signal generation unit generates an imaging signal according to illumination light using a ratio of a period from the exposure start timing of each horizontal pixel line to the switching timing of the illumination light and a period from the switching timing of the illumination light to the exposure end timing in the first and second exposure frames.
