To provide a frame body for filters to which filters of various thickness (or plural filters) are fitted and to/from which the filters are easily attached/detached and a filter used for the same.

A frame body is provided with a first fastening member (an edge frame 6, a fastening bar 5) abutted on one side of a filter and a second fastening member (holes 4, a bar member 3) abutted on the other side thereof. The first fastening member is fixed to the frame body and the second fastening member is positioned at an arbitrary place in the advancing direction of a fluid to be treated (as shown by the arrow A). According to the thickness of the filter, the filter is inserted and fixed between the first fastening member and the second fastening member.