A diaphragm pump for pumping a fluid includes a diaphragm and a driver. The diaphragm has a first surface and a second surface. The driver includes a support portion and is connected to the diaphragm via the support portion. The driver is reciprocated to deform the diaphragm thereby performing a pumping action. The support portion includes a first supporting surface for supporting the first surface and a second supporting surface for supporting the second surface. The support portion allows the diaphragm to slidingly move along an interval between the first and second supporting surfaces when the diaphragm is deformed.