To provide a shredder capable of efficiently using the occupancy area of the shredder itself when the shredder is not used and, thereby, capable of efficiently using a space in an office or a room.

The shredder 1 is provided with: a shredding part 2 in which a shredding mechanism having a shredding blade for shredding paper sheets, etc. is housed; a rubbish throw-in port 3 for throwing in rubbish comprising paper, etc.; and a rubbish housing part 4 capable of housing rubbish shredded by the shredding part 2 and the rubbish comprising paper, etc. so as to be inseparable from each other, wherein a horizontal slide mechanism X1 as a switching mechanism capable of performing switching between a dust projection state P in which the rubbish housing part 4 and the external part are communicated with each other via the rubbish projection port 3 and a shredding state capable of using the shredding mechanism while closing the rubbish projection port 3 without changing the occupancy area in the plan view, is disposed.