A cooling structure of an electric motor comprising a rotor, a stator provided with a wound stator coil, and a housing accommodating the rotor and the stator, wherein a coil end of the stator is spaced apart from an inner wall of the housing. The cooling structure comprises a thermally-conductive member which is provided to thermally connect the housing and the coil end and includes a laminated graphite sheet, and an airbag which is configured to be deployed in a space portion between the inner wall of the housing and the coil end so as to press at least a portion of the thermally-conductive member against the coil end by means of a pressure of pressurized air therein.