The utility model discloses a shredder, which comprises a sealing cover. The sealing cover is positioned in the vicinity of an outlet opening of a shredder casing and is selectively located to prevent the shredded material from being discharged from the outlet opening. The sealing cover is connected with the shredder casing, and a container can be a dismountable waste bin. The sealing cover can enable the container and the shredder casing to be oppositely apart from the working positions thereof and be driven by an actuator to a closing position, for example, when the waste bin is emptied. The sealing cover can reduce or eliminate the waste which is dispersed into the shredder or to the circumference thereof.