In a heat radiating member which has a contact portion to be put into contact with a solid-state image sensor fixed to a prism member, and a fin-like heat radiating portion for radiating heat, which has been transferred through the contact portion, into its surrounding gas, the contact portion and the heat radiating portion are formed from a foil member made of a high heat conductivity material. By mounting the heat radiating member on the solid-state image sensor, there is realized a heat radiating structure for cooling the solid-state image sensor while reducing external-force loads applied to the solid-state image sensor with a relatively simple structure.