Abstract: A micropump capable of delivering very small, predetermined quantities of liquid, e.g. 0.1-100 microliters per stroke, is provided. The pump has a flexible, resilient diaphragm which operates as a movable resilient wall of a pumping chamber, under electromagnetic actuation of a plunger, to cause the pumping action. Other locations of the same resilient diaphragm, in co-operation with curved surfaces on the body structure, act as valves for the inlet and outlet conduits of the pump. The overall size of the pump need be no greater than about 4 cubic cm. Many of the liquid flow conduits therein are formed by co-operating channels or grooves cut in individual co-operating parts of the pump body. The pump may be surgically implanted into a patient's body, to deliver to the desired body location a very small, measured amount of pharmaceutical from an internal or external reservoir thereof, as and when desired.