to the inside and outside up and down or front and back alternately the central push button 56 has a circular column shape having an outer diameter that can be fitted in the circular ring shaped magnet and includes an operation projection 57 on the bottom surface the operation projection 57 is fitted and integrated to and with a concentric disc plate 58 made of magnetic material thus when the central push button 56 is assembled in the circular ring shaped magnet 55 the disc plate 58 is adsorbed and integrated in a separable manner to and with the circular ring shaped magnet 55 to thereby position regulate the central push button 56 the cover plate 60 is a metal thin plate having a substantially square shape in plane that can cover the base 30 and includes an operation hole 61 of a diameter that can prevent the operation member 50 from slipping out at the middle and a caulking hole 62 at four corners the assembly method of the input device made of the above described configuring parts will now be described first a pair of positioning pins or a jig not shown is inserted and positioned in the jig hole 12 of.