A punch die is comprised of: a punch body comprising a punch edge portion at a lower end portion along an axis, a key projecting from an outer periphery, and a punch driver at an upper portion along the axis; a punch guide comprising an inner hollow elongated along the axis and receiving the punch body to be movable along the axis, and a keyway formed on an internal periphery of the inner hollow to extend along the axis and mesh with the key; a retainer collar rotatably combined with the punch guide at an upper end along the axis and around the axis, the punch driver passing through the retainer collar to be movable along the axis; a punch head screwed in an upper end portion along the axis of the punch driver to regulate a position of the punch driver; an elastic member interposed between the punch head and the retainer collar to bias the punch driver upward along the axis; a circular opening formed on an upper surface along the axis of the punch guide and wider than the inner hollow of the punch guide; a plurality of dent portions getting dented radially outward relative to the axis from an internal periphery of the circular opening and being mutually circumferentially spaced; and a press-button supported by the retainer collar, movable in a radial direction relative to the axis, and biased outward, the press-button comprising an engaging portion capable of engaging with any of the plurality of dent portions.