To provide a diaphragm pump capable of reducing the costs and working well irrespective of the number of pump chambers.

Connecting rods 21 and 22 to be coupled with diaphragms 25 and 26 to form pump chambers 23 and 24 are provided in the number corresponding to the number of pump chambers 23 and 24 and mounted in such a way as slidable in common arrangement on the peripheral surfaces of bearings 17 and 18 to bear an eccentric shaft 16. The motions of the two connecting rods 21 and 22 are independent of each other, so that their tips are coupled directly with the diaphragms 25 and 26 with no bearing interposed.