Abstract: The centrifuge has a drive rotating a rotor whose position relative to the vertical axis of the centrifuge is monitored by an unbalance sensor located on the installation plate which is accommodated in a recess of the ring in a plane perpendicular to the vertical axis. The ring is installed on the mounting surface of the drive casing with a provision for being moved and set relative to said surface so that the plane of the ring is constantly parallel with the lower surface of the rotor. The installation plate has a hollow for accommodating the unbalance sensor, the shape of the surface of said hollow being mutually complementary with the shape of the mounting surface of the drive casing and the installation plate is located in said ring with a provision for moving in said plane perpendicular to the vertical axis.