A compound semiconductor device constructed on a heteroepitaxial substrate includes a silicon substrate, a first compound semiconductor layer of a first compound semiconductor material provided on the silicon substrate as a buffer layer, a second compound semiconductor layer of a second compound semiconductor material having a lattice constant larger than that of the first compound semiconductor layer, and an active device provided on the second compound semiconductor layer, wherein the second compound semiconductor layer has a thickness exceeding a critical thickness above which dislocations develop due to the misfit in the lattice constant between the first and second compound semiconductor layers.