A vehicular temperature regulation device includes a refrigeration cycle, a high-temperature cycle, and a low-temperature cycle. The refrigeration cycle includes a heating heat exchanger configured to heat the heat medium in the high-temperature cycle by exchanging heat between the refrigerant and the heat medium, and a cooling heat exchanger configured to cool the heat medium in the low-temperature cycle by exchanging heat between the refrigerant and the heat medium. The vehicular temperature regulation device includes a connection portion that connects the high-temperature cycle and the low-temperature cycle, a regulation portion configured to regulate a flow of the heat medium, and a controller. After the controller stops the compressor, or after the controller receives a stop command of stopping the compressor, the controller controls the regulation portion, a first pump, and a second pump to exchange the heat medium between the high-temperature cycle and the low-temperature cycle.