Abstract: Device (1) for applying bone replacement pastes or bone cements, wherein the device (1) comprises: A) a container-like base part (4) with a first end (5), a second end (6) and a cavity (7), which defines a first longitudinal axis (3), is closed at the first end (5) and is open at the second end (6); and B) a filling piston (8) which can be inserted slidably into the cavity (7) and has a second longitudinal axis (10) and two or more hollow spaces (9) which extend through the filling piston (8) coaxially or parallel to the second longitudinal axis (10) and into which the cannula (13) of the applicator (2) can optionally be inserted.