To fully clean the corner part, at the dead angle, between the inner circumferential end of a reinforcing plate and the outer circumferential face of a filter cylinder, in cleaning the filter cylinder of a screw press equipped with the reinforcing plate on the outer circumferential face of the filter cylinder.

The cleaning device is equipped with a cleaning tube 24 surrounding the outer circumference of the filter cylinder 2 and with a transfer unit 25 for moving this cleaning tube 24 in the axial direction 9 of the filter cylinder 2. The cleaning tube 24 is provided with a plurality of injection nozzles 28a, 28b that injects cleaning water W to the outer circumferential face of the filter cylinder 2. Among these injection nozzles 28a, 28b, one group of injection nozzles 28a inclines forward in the moving direction of the cleaning tube 24, while the other 28b inclines backward, and the two groups of injection nozzles 28a, 28b are in a staggered arrangement with each other.