PURPOSE: To improve a liquid transfer pump used for injecting chemicals into a patient.

CONSTITUTION: A liquid transfer pump comprises a pump part 2 composed of a piezoelectric element and an oscillation circuit for supplying pulse voltage to the pump part 2, and a liquid inlet pipe 5 and a liquid outlet pipe 6 in which check valves 3, 4 are arranged are installed to the pump part 2. The simple structure and the easy liquid flow rate control and transfusion set installation facilitates the operation by an operator, and the production cost reduction allows it to be used once and thrown away (disposable).