A steering wheel grip detection device includes a positive electrode terminal electrically connected to a positive electrode of a power source and a negative electrode terminal electrically connected to a negative electrode of the power source. The steering wheel grip detection device further includes a thermostat, a heater, and an inductance element that are electrically connected with one another in this order in series wiring from the positive electrode terminal to the negative electrode terminal, as well as a capacitor through which a wiring path from the thermostat to the heater is electrically connected with the negative electrode terminal. The steering wheel grip detection device has an electrostatic sensor circuit that is electrically connected with a wiring path from the inductance element to the heater and that detects a grip on a steering wheel by a capacitance value of the heater.