Flexible circuits 2, 3 are formed on a flexible insulating sheet 1. A thermal sensor 4 is connected between the circuits 2, 3. The thermal sensor 4 and connecting parts 5 are integrally covered with an elastic insulating resin 6. While the insulating sheet 1 is bent together with the insulating resin 6, the thermal sensor 4 is pushed onto an object to be sensed 8 via the insulating sheet 1. A plurality of thermal sensors 4 are connected in series in a longitudinal direction of the insulating sheet 1. The insulating resin 6 covers the thermal sensors 4 and the connecting parts 5.