A manufacturing method of an electronic device processes a surface of a first wafer, bonds a surface of a second wafer to the processed surface of the first wafer, thins the first wafer by polishing a back surface of the first wafer, the back surface being located on an opposite side of the processed surface, forms a groove along a periphery of the back surface of the thinned first wafer by using a dicing blade, attaches a protective layer to the back surface of the first wafer having the groove, via a bonding layer, and polishes a back surface of the second wafer, the back surface being located on an opposite side of the surface attached to the protective layer.