To provide a dehumidifying and heating device capable of detecting abnormal drainage of dehumidified water to prevent overflow of the dehumidified water in a simple configuration.

A dehumidifying and heating device includes a heat pump device 9 having a compressor 4, a radiator 5, a throttle device 6, and a heat sink 7, which are connected by piping 8 through which a cooling medium circulates; an air circuit 16 in communication from an air flow inlet 2 through the heat sink and the radiator with an air flow outlet 3; a circulation fan device forming an air flow within the air circuit; a drain pan 10 receiving dehumidified water produced by dew condensation resulting from heat exchange with air in the heat sink; an outflowing air temperature sensor 12 disposed so as to detect the temperature of the air within the air circuit at the air flow outlet; and a control device 15 controlling the operation of the compressor. The control device calculates a temperature change rate from an outflowing air temperature detection value obtained by sampling the outflowing air temperature signal based on the detected signal of the outflowing air temperature sensor at intervals of Δt seconds, and controls the operation of the compressor to be stopped when the temperature change rate falls below a change rate reference value.