Abstract: Disclosed is a temperature-sensitive actuator which is configured in such a manner that heat from a PTC heater for the temperature-sensitive part of a thermoelement can be received appropriately and reliably in a required state. Specifically disclosed is a temperature-sensitive actuator (10) which is configured to sense the temperature although a piston (14) is operated forcibly by generating heat from a PTC heater (20) and warming the temperature-sensitive part (13) of a wax thermoelement, wherein a contact member (40) is interposed between the temperature-sensitive part of a thermoelement and the PTC heater. Consequently, variation in the amount of heat which is received at the temperature-sensitive part of a thermoelement from the PTC heater is limited, and the stabilized output (lift) of the thermoelement can be ensured.