A silicon carbide semiconductor device includes a gate insulating film and a gate electrode. A first main surface is provided with a trench defined by a side surface penetrating a third impurity region and a second impurity region to reach a first impurity region, and a bottom provided continuously with the side surface. In a stress test in which a gate voltage of at least one of −10 V and 20 V is applied to the gate electrode for 100 hours at a temperature of 175° C., where a threshold voltage before the stress test is defined as a first threshold voltage and a threshold voltage after the stress test is defined as a second threshold voltage, an absolute value of a difference between the first threshold voltage and the second threshold voltage is not more than 0.25 V. The second threshold voltage is not less than 2.5 V.