To provide a heat radiating device that has small restrictions on the shape or arrangement of respective members, excellent heat radiating efficiency and a large effect of reducing weight and is suitably used for a small-size electronic part or device.

The heat radiating device has a heat receiving part that is provided on a product having a built-in heating body and receives heat from the heating body, a heat transmitting part for transmitting the received heat, a heat radiating part for radiating the transmitted heat to the outside of the product, and a holding member for integrally holding the heat receiving part, the heat transmitting part and the heat radiating part as a cooling unit. At least part of the holding part of at least the heat transmitting part of the holding member is made of resin.