In cold weather, fogging on a windshield in a vehicle disturbs the driver's view and leads to the threat for the safety of the vehicle and passengers. Air-conditioning units for dehumidifying and engine coolant for heating has been used in combustion engine vehicles. However, in electric vehicles, since the electric heater instead of the engine coolant is used for heating, the dehumidifying and heating process causes higher power consumption. As an efficient dehumidifying and heating, a heat pump system is available. The objective of this study is to investigate the feasibility of the heat pump for dehumidifying and heating and to compare the performance of the heat pump with that of an air-conditioning unit and an electric heater. The heat pump showed higher dehumidifying and heating performance than those of an air-conditioning unit and an electric heater.