Abstract: A heating unit can reduce the rate of power consumption for heating a vehicle, so that the running distance of the vehicle is increased and hence the battery charging cycle of the vehicle is prolonged. A heating unit of a vehicle heating system includes a casing made of a metal material capable of electromagnetically shielding microwaves, a support arranged in the hollow section of the casing, a plurality of microwave absorbing/heat emitting members arranged at the support and a microwave outputting unit arranged in the casing to output microwaves toward respective microwave absorbing/heat emitting members, blown air being heated by heat generated as a result of absorption of microwaves by the microwave absorbing/heat emitting members at the time for blown air to flow from the upstream side to the downstream side in the hollow sections of the microwave absorbing/heat emitting members.

Abstract: A heating unit can reduce the rate of power consumption rate for heating a vehicle, so that the running distance of the vehicle is increased and hence the battery charging cycle of the vehicle is prolonged.

Abstract: A microwave oscillator is effectively cooled and its output characteristic is stabilized, while the waterproof property of the microwave oscillator is secured. Additionally, the heat of the air heated as a result of cooling the microwave oscillator is discharged effectively to maintain the cooling effect. Furthermore, the cooling structure of the microwave oscillator is simplified and downsized and the cost of the arrangement is reduced. A structure includes an air blower member for blowing air to a microwave oscillator and a heat radiating/air circulating member airtightly connected to the terminating end of a microwave waveguide and a shield box so as to be able to cool the air introduced into the microwave waveguide after cooling the microwave oscillator as the air blower member is driven to by turn drive the air to flow from the terminating end toward the shield box. The air in the shield box and the microwave waveguide is enabled to circulate.