To improve the responding property of a bimetal type thermal switch and provide a thermal switch usable as a sensor to be used at the time of deep frying.

A supporting part 13 is formed in the inside of a housing 11 and the circumferential end part of a bimetal disk 14 which has approximately a disk-like shape and has a feature of deforming unevenly following fluctuation of the temperature is brought into contact with the part 13. The circumferential end part of the disk is pushed by a spring 15 and pressed to the supporting part. Consequently, without interfering the deformation of the disk, heat is transmitted surely and reliably from the housing to the disk through the supporting part.