According to an embodiment, an imaging device includes a first CCD which converts a first color component into a first electric signal, a second CCD which converts a second color component different from the first color component into a second electric signal, a third CCD which converts a third color component different from the first and second color components into a third electric signal, and a heat sink having first to third radiators which radiate heat from the first to third CODs. The first to third radiators are maintained at the same temperature by the function of the heat sink.