To provide a fixing device including the configuration in which the generation of the abnormal image due to the generation of contact marks is prevented in the case where a temperature detecting member of a contact system is used, and temperature detection accuracy can be assured without entailing a cost increase.

The fixing device is equipped with the contact type temperature detecting member 76 disposed contactually on the surface of the fixing member 74 as a temperature detecting member of a heat source 73A used for heat fixing. The contact type temperature detecting member 76 is previously provided with an oil layer 75B provided with a width (W1) narrower than the width (W0) of the contact surface on the side coming into contact with the fixing member 74, and is incorporated into the fixing member 74 so as to come into contact therewith.