An impact head includes an arm member moving to a protruding position when a magnetic flux is generated and to a return position when the magnetic flux disappears; an impact member connected to the arm member for protruding when the arm member moves to the protruding position and returning to an original position when the arm member moves to the return position; and an urging member for urging the arm member with a restricted urging force when the magnetic flux is generated and urging the arm member to the return position when the magnetic flux disappears.