To solve such problems with a diaphragm air pump having an electromagnetic reciprocating driving device used as a drive source and a switch mechanism used for interrupting a power when a diaphragm is damaged that (1) a part of a lever part may be damaged when the switch mechanism is operated and the part thereof must be replaced to recover to the original state and (2) since the definite setting of the positions of a stroke and an over stroke are normally hard, the positions must be set with a considerable allowance taken into account and the operation is not reliable.

This electromagnetic reciprocating driving device comprises a stator having electromagnetic coils 5 and 5'. A needle 4 having a shaft 1 with a permanent magnet 3 is installed so as to be axially reciprocated by the interaction thereof with a magnetic field formed by the electromagnetic coils. A flux detection means 20 is installed at a position where the detected amount of magnetic flux of the needle is different between the positions of the stroke and over stroke.