A novel and improved temperature detecting device for detecting the temperature of a vehicular clutch is disclosed which is able to provide an accurate voltage across the electromagnetic clutch by taking account of a voltage drop across power supply elements inside the clutch and a voltage drop in wiring due to a current flowing through the clutch, improve the accuracy in detection of the clutch temperature, and have high reliability and commerciality for vehicular use. To this end, a clutch voltage sensing element senses a voltage across an electromagnetic clutch. A clutch current calculating element generates a clutch current command signal, which controls the current supply to the electromagnetic clutch, and a clutch cut-off signal based on engine control information data and travel control information data of a vehicle. The clutch current calculating element calculates the electric resistance of the electromagnetic clutch based on the clutch voltage sensed by the clutch voltage sensing element and on the clutch current command signal so as to determine the actual temperature of the electromagnetic clutch. A clutch current controller controls the current supply to the electromagnetic clutch based on a deviation between the clutch current command signal and a current feedback signal representative of a clutch current flowing through the electromagnetic clutch, and on the clutch cut-off signal.