We successfully grew epitaxial MnAs∕GaAs superlattices at various growth temperatures (Tg) with a periodicity of 5∕5nm using molecular-beam epitaxy and characterized their magnetic and electrical transport properties. Structural analysis shows that the magnetic anisotropy originates from the crystal domain structure of the MnAs layers. The metallic behavior for the sample with Tg=375°C systematically changed to semiconducting on increasing Tg up to 540°C. The transport properties of thin single layered MnAs films with a thickness of 20nm showed the same Tg dependency. These observations indicate that the semiconducting characteristics of MnAs∕GaAs superlattices are attributable to a radical alteration of the electronic structure of the MnAs layers.