To provide a dust collector in which dust or the like stuck to a filter can be efficiently brushed off during the stop of the operation and in which suction force deterioration due to clogging of the filter can be prevented.

A dust collector 10 has a dust collection box 23 for storing dust sucked in from a suction port. The dust collector includes: a negative pressure generating means 11 for generating a negative pressure inside the dust collection box 23; a filter 21 provided on the suction side of the negative pressure generating means 11; and a tension imparting means 31 imparting a tension to the filter 21. The tension imparting means 31 imparts a tension in a direction against deformation of the filter 21 caused by operation of the negative pressure generating means 11.