A layer comprising silicon oxide (SiO2) is formed on (111) plane of a silicon (Si) substrate in a striped pattern which is longer in the [1-10] axis direction perpendicular to the [110] axis direction. Then a group III nitride compound semiconductor represented by a general formula AlxGayIn1−x−yN (0≦x≦1, 0≦y≦1, 0≦x+y≦1) is laminated thereon. The group III nitride compound semiconductor represented by a general formula AlxGayIn1−x−yN (0≦x≦1, 0≦y≦1, 0≦x+y≦1) grows epitaxially on the substrate-exposed regions B which are not covered by the SiO2 layer, and grows epitaxially on the SiO2 layer in lateral direction from the regions B. Consequently, a group III nitride compound semiconductor having no dislocations can be obtained.