An endoscope includes an insertion portion which is to be inserted into a subject, and an operation portion which is connected to a proximal end of the insertion portion, and held by a user. A light source is provided in the operation portion. A heat transmission frame is provided with the light source in the operation portion, is able to transmit heat generated by the light source, and is at least partially electrically insulated. An external heat radiation part is connected to the heat transmission frame, is at least partially exposed to the outside of the operation portion, and radiates heat transmitted to the heat transmission frame to the outside of the operation portion.