To obviate the occurrence of any contraflow air by a check valve even in the case where such a trouble as breaking a valve chest case has occurred in one side of the two-connected pump elements.

This diaphragm pump 1 stores dual pump parts 2, installing a diaphragm for partitioning a pump case and a drive chamber in a valve chest case, pulsating this diaphragm by means of a magnetic interaction between a moving piece with a permanent magnet installed in this drive chamber and n electromagnet, performs the suction and discharge of air from or to the outside in one outer case 8, and exhaust the discharge air emitted out of each discharge opening of these pump parts 2 to the outside by way of a silencer chamber 9. Two check valves 16 for preventing any contraflow of air into the pump parts 2 from the discharge opening 11 are set up in an interval from each pump part 2 to the silencer camber 9 where the discharge air is mixed, at the more downstream side than the discharge opening 11 of these dual pump parts 2.