To provide a temperature control device of a hybrid automobile which can always travel in the optimal condition by controlling a changeover means for making an engine housing communicate with a battery housing and cutting off both of them on the basis of the indication of a sensor for detecting the temperature of both of them.

A temperature control device is constituted so that the output of sensors 28, 30 for detecting the temperature of a battery 12 and an engine 16 is inputted to a microcomputer 32 to control the operation of solenoid valves 24, 26 for changing over communication and isolation between an engine housing 18 and a battery housing 14, a fan 22 for sending a hot wind and a fan 34 for cooling a ceramic heater 23 and a battery. The solenoid valves 24, 26 are a four way type valve and a three way type valve which are operated by a solenoid, and the temperature sensors 28, 30 are a thermoelectric couple. Therefore, since an engine and a battery are warmed up by utilizing wasted heat, additional energy is not consumed, the starting property of an engine is enhanced and the original performance of a battery can be demonstrated.