The purpose of the present invention is to provide a filter device with which, when used in combination with an atherectomy device, the location of a filter can be easily changed, and an embolus can be efficiently captured. The present invention provides a filter device provided with: a core material； an extrusion member； a first tube； a second tube； a third tube； a first limiting member which is disposed on the first tube and limits extrusion of the third tube toward a distal end side； a filter； a ring fixed to the opening portion； a first wire； and a second wire. The filter, when the extrusion member fixed on the core material is pushed while being in contact with the second tube, the shape of the ring becomes deformed by the first wire and the second wire and an opening diameter is reduced. As the extrusion member fixed on the core material is separated from the second tube, the shape of the ring recovers and the opening diameter is increased.
