PURPOSE: To manufacture a sintered body having high quality with a small capacity and low cost electric power source device by arranging high voltage power source and low voltage power source at the time of manufacturing the desired body with electric discharge sintering and executing the desired electric conduction from these power sources according to resistance of the sintering body during sintering.

CONSTITUTION: The sintering body 4 is set in a die 1, and a punch 3 is descended with hydraulic cylinder 5 to pressurize the body 14 to be sintered between the punch 3 and an electrode 2 for electric conduction. At the same time, by working inverter circuit 7, the output of the circuit 7 is transformed into the desired voltage through a transformer 8, and by impressing the power between the electrode 2 and the punch 3, the electric discharge sintering is executed. Then, at the initial stage of pressurization, a switching element 12 is turned to 'on' and the sintering is executed at the high voltage of e.g., about 30V, and the switching element 12 is momentarily turned to 'off' at every interval of prescribed times during sintering, and during this, a switching element 15 is closed and the resistance of the body 4 is measured with a resistance detector 17. Based on this measurement, the control device 18 discriminates a condition of progress of the sintering and change-over into the switching elements 13, 14 is executed in order so as to sinter with lower voltage according to the value of resistance.