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 13 three-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 17 and the second wiring layer 13, and therefore close the switch 10.