A silicon carbide semiconductor device that includes J-FETs has a drift layer of epitaxially grown silicon carbide having a lower impurity concentration level than a substrate on which the drift layer is formed. Trenches are formed in the surface of the drift layer, and first gate areas are formed on inner walls of the trenches. Second gate areas are formed in isolation from the first gate areas. A source area is formed on channel areas, which are located between the first and second gate areas in the drift layer. A method of manufacturing the device ensures uniform channel layer quality, which allows the device to have a normally-off characteristic, small size, and a low likelihood of defects.