There is provided a substrate for electronic devices, in which treatment for forming a reconstructed surface or a hydrogen-terminated surface on a substrate is not necessary, and a buffer layer formed on the substrate can be epitaxially grown in the (100) orientation, and a manufacturing method therefor. The substrate 100 for electronic devices comprises; a substrate 11 consisting of silicon, and a first buffer layer 12 and a second buffer layer 13 having a fluorite structure, a first oxide electrode layer 14 having a layered perovskite structure, and a second oxide electrode layer 15 having a simple perovskite structure, which are epitaxially grown and laminated in this order on a film-forming surface of the substrate 11. The first buffer layer 12 is grown epitaxially at a higher rate than the growth rate of SiO₂, by irradiating a metallic plasma onto a natural oxide film in an SiO sublimation area.