Disclosed is a power resistor which has a large heat capacity per unit volume and an appropriate and stable electrical resistance, and in which the resistance changes little with time due to surge absorption. This power resistor includes a sintered body containing aluminum oxide and carbon, and a pair of electrodes formed on the two opposing surfaces of the sintered body. This sintered body consists of first regions containing a small amount of carbon or not containing carbon and second regions containing a larger amount of carbon than in the first regions and so arranged as to be connected to the electrodes.