To provide a filter adapter to which an optical filter of optimum filter diameter can be attached without causing upsizing of a lens barrel itself, and in which the length of the lens barrel in the optical axis direction can be shortened in a state of the lens barrel attached to a camera body when it is collapsed.

A filter adapter includes: fixed tubes 2, 4 detachably attached to a camera body in a state that they are externally inserted to a zoom lens barrel; a movable tube 3 held to be movable in the axial direction with respect to the fixed tubes 2, 4, having on its tip portion a lens barrel pressing part 3a extending radially inward, and to which an optical filter 1 is detachably attached on an object side end part from the lens barrel pressing part 3a; and an energization component 5 arranged between the fixed tube 4 and the movable tube 3 and energizing the movable tube 3 toward the camera body side. When the lens barrel extends toward the object side, the lens barrel pressing part 3a is pressed by the tip portion of the lens barrel against the energizing force of the energization component 5, thereby the movable tube 3 moves in the optical axis direction in linkage with the lens barrel.