A container filling machine includes at least one filling spout, and a cleaning device including a stationary collecting member with a passage opening, a sealing member that can be displaced between a retracted position and a service position in which said sealing member is capable of tightly sealing the passage opening, and displacement means for displacing said sealing member between the retracted position and the service position thereof. The sealing member includes an elastically deformable membrane mounted on a holder and forming therewith a tight deformation chamber capable of receiving a pressurized fluid in order to deform the deformable membrane for sealing the passage opening when said holder is displaced into the service position by the displacement means.