A method for manufacturing a SiC semiconductor device includes: forming an impurity layer in a SiC layer; and forming an oxide film on the SiC layer. The forming the impurity layer includes: implanting an impurity ion in the SiC layer; forming a carbon layer on the SiC layer; heating the SiC layer for activating the implanted impurity in the SiC layer covered with the carbon layer; and removing the carbon layer from the SiC layer. The forming the carbon layer includes: coating a resist on the SiC layer; and heating the resist for evaporating organic matter in the resist so that the resist is carbonized. The forming the oxide film is performed after the removing the carbon layer.