A method of manufacturing a wide band gap semiconductor device includes the steps of preparing a wide band gap semiconductor substrate, separating the wide band gap semiconductor substrate into a plurality of first semiconductor chips, fixing the plurality of first semiconductor chips on a fixation member, measuring a breakdown voltage of each of the first semiconductor chips while immersing at least the first semiconductor chips in inert liquid, and after the step of measuring a breakdown voltage of each of the first semiconductor chips, providing a plurality of second semiconductor chips each having each of the first semiconductor chips fixed on the fixation member, by cutting the fixation member.