PURPOSE: To further effectively wind an end of a skin material by elastically deforming an elastic wall by rotating a first presser and elastically deforming an elastic wall by allowing a second presser to protrude.

CONSTITUTION: A first presser 25 is rotated toward a mounting part 12 at a fulcrum part 24 of a hinge 22 as a fulcrum, and a pressing part 26 presses an outer surface 17a of an elastic wall 15. An elastic wall 15 pressed at an outer surface 17 is elastically deformed while drawing a trace of substantially a circular-arc state while being compressed, and wound to a rear surface side of a base material 41 while an end 42a of a skin material 42 protruding from an end 41a of the base material 41 is being bent. Then, a second air cylinder 35 is driven while a state that a piston 33 of a first air cylinder 31 protrudes remains, and a piston 37 protrudes from a case 36. A second presser 38 fixed to an end presses an upper surface 18 of the wall 15 in this state.