An automated high-precision plunger pump for volumes of less than 1 microliter, which is used in the microscope-assisted micromanipulation of biological material, comprises a housing (1) and a pump head (8) that defines a working chamber (9) with a common or separate inlet and outlet opening (10), wherein the volume of the working chamber (9) can be altered by an axially movable plunger (7) that can be introduced into it. The plunger (7) is axially movable via a threaded spindle (5) or a spindle nut (6) arranged in threaded engagement on the threaded spindle (5), and the threaded spindle (5) and/or the spindle nut (6) can be rotationally driven and the respective other component is designed to be rotationally lockable.
