Abstract: Washing device for one or more pleated cartridges (3) comprising a pleated filtering membrane (4) arranged around a perforated tube (5). Said washing device comprises a casing (1) which is provided with at least one discharge opening (9) and is suitable for containing said cartridges (3), as well as at least one motor (11) provided with a transmission member (13) suitable for being coupled in a removable manner with said cartridges (3) so as to rotate them around their longitudinal axis, wherein said casing (1) includes one or more nozzles (7) which are suitable for being supplied with washing liquid by at least one supply duct (8) and are turned towards the cartridges (3) for spraying the washing liquid toward the eternal surface of their pleated membrane (4) during the rotation imparted by said motor (11). The present invention also relates to a filter comprising said device.