PROBLEM TO BE SOLVED: To provide a heat radiator of a substrate, in which heat that an imaging element and components, which are connected to the substrate, generate is efficiently radiated.SOLUTION: When a first imaging element 110 emits heat, the heat is transmitted to a first heat radiation member 180 through pattern wiring 161 and vias 162. The first heat radiation member 180 transmits the heat from a rear end face 183 to a braided wire 143. The heat is radiated through the braised wire 143. Heat transmitted to the first heat radiation member 180 through the first substrate 150 and the pattern wiring 161 is liable to return again to the first substrate 150 and the first imaging element 110. Thus, air having thermal conductivity which is much lower than that of a material of the first substrate 150 is arranged at a periphery of the first heat radiation member 180 as a heat insulator to prevent the heat transmitted to the first heat radiation member 180 from returning to the first imaging element 110.
