A container emptying device for emptying at least one container, such as a container drum, filled with a liquid, comprising a suction unit, a receiving unit and a pipe unit connecting the receiving unit with the suction unit, wherein the suction unit comprises at least one suction lance adapted to be inserted and lowered into the at least one container, at least one pump, connecting the at least one suction lance with the pipe unit, for pumping the liquid out of the at least one container, a control device for controlling a suction process, and wherein the pipe unit comprises at least one flexible pipe for transporting the liquid out of the at least one container characterised in that the receiving unit comprises a buffer tank for receiving the liquid sucked out of the at least one container by the suction unit a cleaning-in-place subunit for cleaning the buffer tank and/or the suction unit and/or the pipe unit and/or the at least one container and in that the cleaning-in-place subunit comprises an inlet for a cleaning agent and an outlet for a used cleaning agent, the inlet being arranged and adapted to feed the cleaning agent into a cleaning circuit consisting of the buffer tank, the at least one suction lance lowered into the buffer tank and the pipe unit, and the outlet being arranged and adapted to receive and dispose of used cleaning agent from said cleaning circuit. at least one suction lance adapted to be inserted and lowered into the at least one container, at least one pump, connecting the at least one suction lance with the pipe unit, for pumping the liquid out of the at least one container, a control device for controlling a suction process, and wherein the pipe unit comprises at least one flexible pipe for transporting the liquid out of the at least one container characterised in that the receiving unit comprises a buffer tank for receiving the liquid sucked out of the at least one container by the suction unit a cleaning-in-place subunit for cleaning the buffer tank and/or the suction unit and/or the pipe unit and/or the at least one container and in that the cleaning-in-place subunit comprises an inlet for a cleaning agent and an outlet for a used cleaning agent, the inlet being arranged and adapted to feed the cleaning agent into a cleaning circuit consisting of the buffer tank, the at least one suction lance lowered into the buffer tank and the pipe unit, and the outlet being arranged and adapted to receive and dispose of used cleaning agent from said cleaning circuit. a buffer tank for receiving the liquid sucked out of the at least one container by the suction unit a cleaning-in-place subunit for cleaning the buffer tank and/or the suction unit and/or the pipe unit and/or the at least one container and in that the cleaning-in-place subunit comprises an inlet for a cleaning agent and an outlet for a used cleaning agent, the inlet being arranged and adapted to feed the cleaning agent into a cleaning circuit consisting of the buffer tank, the at least one suction lance lowered into the buffer tank and the pipe unit, and the outlet being arranged and adapted to receive and dispose of used cleaning agent from said cleaning circuit. an inlet for a cleaning agent and an outlet for a used cleaning agent, the inlet being arranged and adapted to feed the cleaning agent into a cleaning circuit consisting of the buffer tank, the at least one suction lance lowered into the buffer tank and the pipe unit, and the outlet being arranged and adapted to receive and dispose of used cleaning agent from said cleaning circuit.