An imaging device that reduces differences between a bird's eye image and an actually measured distance includes imaging cameras mounted on a ship to capture peripheral images of the ship and combines the peripheral images captured by the imaging cameras to create the bird's eye image as a composite image. The imaging device includes an auxiliary camera adjacent to at least one of the imaging cameras, and a distance calculator that calculates a distance in a lateral direction using the auxiliary camera and the at least one of the imaging cameras adjacent to the auxiliary camera.