In a super-junction structure of a power MOSFET or the like, the concentration of a main body cell portion is relatively high so that it is difficult to ensure a breakdown voltage equal to or higher than that of the cell portion for a peripheral portion using a related-art peripheral termination structure or resurf structure. Specifically, a problem arises such that, in an outer peripheral corner portion of a chip, due to electric field concentration, variations in breakdown Voltage become sensitive to charge unbalance in the super-junction structure. In the present invention, in a semiconductor power device such as a power MOSFET having a super-junction structure in each of an active cell region and a chip peripheral region, an outer end of a surface resurf region of a second conductivity type coupled to a main junction of the second conductivity type in a surface of a drift region of a first conductivity type and having a concentration lower than that of the main junction is located in a middle region between an outer end of the main junction and an outer end of the super-junction structure in the chip peripheral region.