A semiconductor wafer is provided with a thick region extending along its outer circumferential surface and being greater in thickness than its central region. A main surface of the wafer includes a slope surface located between the central region and the thick region. The slope surface has an inner circumferential edge and an outer circumferential edge, and slopes such that the thickness of the wafer increases from the inner circumferential edges to the outer circumferential edge. The slope surface includes an inner circumferential portion including the inner circumferential edge, an outer circumferential portion including the outer circumferential edge and an intermediate portion located between the inner and the outer circumferential portions. At least one of slope angles of the inner and the outer circumferential portions is smaller than a slope angle of the intermediate portion.