To provide a manufacturing system of a synthetic oil mixed with a metal powder having heat resistance and heat discharging property, and capable of using for a long time as a synthetic oil mixed with a metal powder synthesized by mixing a large quantity of a metal powder with an arbitrary oil material.

In this manufacturing system of a synthetic oil mixed with a metal powder, a ultrasonic mixing synthesizing unit 3 is connected to an arbitrary metal powder storage tank 1 via a solenoid valve 10 and a pump 15, and to an oil storage tank 2 via a solenoid valve 11 and a pump 16, and a ultrasonic vibration unit 6 which is connected to a ultrasonic power generation unit 5 with cables 5A and 5B is set in the ultrasonic mixing synthesizing unit 3. The ultrasonic mixing synthesizing unit 3 is connected to a metal powder-mixed synthetic oil storage tank 8 via a solenoid valve 12, a metal powder-mixed synthetic oil component detecting sensor 7, a pump 18, and a solenoid valve 13. A solenoid valve 14 and a pump 17 are set between the ultrasonic mixing synthesizing unit 3, and a point between the metal powder-mixed synthetic oil component detecting sensor 7 and the solenoid valve 13. A control unit 4 is connected to the ultrasonic power generation unit 5, solenoid valves 10, 11, 12, 13, and 14, an upper sensor 9, and a lower sensor 9A, and the control unit 4 is connected with the metal powder-mixed synthetic oil component detecting sensor 7 by a detected data transmission circuit 7A.