A miniature pump equipped with: a pump chamber communicated with a suction port by way of a check valve and communicated with a discharge port by way of another check valve; a driving portion for performing a pump function by increasing and decreasing a volume of the above described pump chamber; a driving plate attached to the above described driving portion for reciprocating the driving portion; a rotating plate fixed to an output shaft of a motor; a ball disposed at a location which is between the above described driving member and the above described rotating plate, and apart from the above described output shaft; and means for applying a force to a surface of the above described driving plate on a side of the above described rotating plate for bringing the above described driving plate into close contact with the above described ball, in which an inclined direction of the above described driving plate is continuously changed by a movement caused due to rotations and revolutions of the above described ball as the above described rotating plate rotates, thereby reciprocating the above described driving portion and performing a pump function.