PURPOSE: To provide a supply air pressure variable type air pump device formed so as to supply air of preset air pressure.

CONSTITUTION: A device has a pump unit 2, control part 3 for controlling the pump unit 2 actuated, display part 4 and an air supply circuit 5. The air supply circuit 5 has a route of passing the first supply tube 8 via a branch pipe 6 and a check valve 7 from the pump unit 2 and a route of passing the second supply tube 10 via the branch pipe 6 and a check valve 9 from the pump unit 2. Leak valves 11, 12 for relieving air, when generated about 32mmHg or more, are branch-connected to the first/second supply tubes 8, 10. Further in the first supply tube 8 in the air supply circuit 5, a pressure sensor 20 for detecting an air pressure in the tube is provided. Thus even for an air pad set to an air pressure lower than a blood flow inhibiting pressure of a peripheral capillary, the device can be applied.