An imaging unit includes an imaging device that transmits an image data to an external display device; and an installation portion that is attachable to and detachable from the display device. The imaging device includes a communication part that transmits an image data to the display device, an outer barrel, and an imaging element. The installation portion includes a slider that is slidable with respect to the outer barrel, a first attached body that is connected to the slider, a second attached body that can change its gap with the first attached body, and a biasing member that biases the first attached body and the second attached body in a direction in which a gap therebetween becomes narrowed, in which the display device is grasped by the first attached body and the second attached body.