An apparatus for a friction stir and a friction stir processing of the present invention suppress an occurrence of a surface defect in an area processed by the friction stir. The apparatus for the friction stir includes a tool having a columnar tip-side part, a rotating unit for rotating the tool on a central axis, a first pressing unit for pressing a tip of the tool rotated by the rotating unit against a work, a jig having a tool insertion hole into which the tip-side part of the tool is inserted so that the tip-side part of the tool is encircled around the jig, a second pressing unit for slidably pressing the jig against the work, and a press control unit for controlling the first pressing unit so that the tip-side part of the tool is gradually pulled out of the work by the first pressing unit while moving the tool and the jig relative to the work, in a state that the tool is rotated by the rotating unit and the tip of the tool has been sunk into the work to a predetermined depth by the first pressing unit.