A semiconductor device manufacturing method of an embodiment includes forming a first layer in a region of a first substrate excluding an outer peripheral portion thereof; forming a first semiconductor circuit above the first layer; for a second semiconductor circuit on a second substrate; forming a second layer with a predetermined width at an outer peripheral portion of the second substrate; bonding a surface of the first substrate on a side provided with the first semiconductor circuit and a surface of the second substrate on a side provided with the second semiconductor circuit; and applying tensile stress to the first layer and the second layer to debond the first layer and the second layer, thereby forming the second substrate including the first semiconductor circuit and the second semiconductor circuit.