A problem in the conventional technique is that metal contamination on a silicon carbide surface is not sufficiently removed in a manufacturing method of a semiconductor device using a monocrystalline silicon carbide substrate. Accordingly, there is a high possibility that the initial characteristics of a manufactured silicon carbide semiconductor device are deteriorated and the yield rate is decreased. Further, it is conceivable that the metal contamination has an adverse affect even on the long-term reliability of a semiconductor device. In a manufacturing method of a semiconductor device using a monocrystalline silicon carbide substrate, there is applied a metal contamination removal process, on a silicon carbide surface, including a step of oxidizing the silicon carbide surface and a step of removing a film primarily including silicon dioxide formed on the silicon carbide surface by the step.