A semiconductor device includes a first temperature sensor module, a second temperature sensor module, a first temperature controller, and a second temperature controller. The first temperature sensor module includes a bandgap reference circuit that outputs a plurality of divided voltages, and a first conversion circuit that performs analog-to-digital conversion processing on one of the plurality of divided voltages to generate a first digital value. The second temperature sensor module includes a second conversion circuit that performs analog-to-digital conversion processing on the one of the plurality of divided voltages to generate a second digital value. The first temperature sensor controller converts the first digital value to a first temperature. The second temperature sensor controller converts the second digital value to a second temperature. The semiconductor device determines whether the first and second temperature modules operate normally based on a difference between the first temperature and the second temperature.