To obtain a stable good sensor characteristic by ensuring the contact between a bimetal and a cap to improve the thermal response characteristic, and simplifying and facilitating a bimetal assembling process to improve the work efficiency in a bimetal type temperature sensor.

In a sensor including a case, a cap and a bimetal 35, in which the bimetal 35 senses heat through the cap to perform reversing operation, thereby detecting the temperature, there is provided a fitting pressing spring 30 for holding the bimetal 35 in a reversible operation enabled state. The bimetal 35 is held by the fitting pressing spring 30, and the force of pressing toward the cap (m-direction) is always applied by the spring force of the fitting pressing spring 30. The fitting pressing spring 30 includes plural click parts 33 for holding the peripheral part of the bimetal 35 in plural places, and plural spring parts 32 for pressing the bimetal 35 toward the cap in plural places.