There is provided a semiconductor device including an ohmic junction layer which is excellent in surface flatness and uniformity of composition in an interface with a semiconductor substrate and thus can give a sufficiently high adhesiveness with a Schottky junction layer. Such a semiconductor device includes an n type SiC semiconductor substrate (1), a cathode electrode (5) that comes into ohmic contact with a main surface (1b) of one side of the SiC semiconductor substrate (1), a first semiconductor region (6a) that is made of p type SiC formed in a main surface (1a) of the other side of the SiC semiconductor substrate (1), a second semiconductor region (6b) that is made of an n type SiC formed in the main surface (1a) of the other side, an ohmic junction layer (7) that comes into ohmic contact with the first semiconductor region (1a), and a Schottky junction layer (8) that comes into Schottky contact with the second semiconductor region (6b), wherein a root mean square roughness for a surface of the ohmic junction layer (7) is 20 nm or less.