A first wiring layer 16 is disposed on an insulating film 14 on the lower surface of an upper substrate 15, while a second wiring layer 13three-dimensionally crossing the first wiring layer 16 is provided on the insulating film 12 on a lower substrate 11. A cantilever 17 has one end connected to the first wiring layer 16 and the other end opposed to the second wiring layer 13 with a space therebetween. A thermoplastic sheet 19 is arranged on the upper substrate 15 so as to cover the through-hole 18. The thermoplastic sheet 19 is pressed by a heated pin 20 against the cantilever 17 and deformed so as to maintain the connection between the cantilever 17and the second wiring layer 13, and therefore close the switch 10.