To easily, quickly and reliably install these by fixing a switch case and a magnet holding plate to a cover and a shift knob by a pressure sensitive adhesive double coated tape.

A magnet holding plate 10 is fixed so as to be opposed to a switch case 7 under a shift knob 1 positioned at a 'P' point 5 by having an interval of about 5mm from a tip part of a switch case 7. Fixation to a cover 3 of the switch case 7 in which a reed switch is internally arranged and fixation to the shift knob 1 of the magnet holding plate 10 are adhesively performed by using a pressure sensitive adhesive double coated tape respectively adhered and fixed to a bottom surface of the switch case 7 and a back face of the magnet holding plate 10. Therefore, fixation to the cover 3 of the switch case 7 in which the reed switch is internally arranged and fixation to the shift knob 1 of the magnet holding plate 10 can be extremely easily and quickly performed.