PURPOSE: To accurately detect the pressure by providing a resistance circuit base having a couple of electrodes and a block contact forming a parallel variable resistance circuit electrically keeping contact with the base at all times.

CONSTITUTION: The resistance circuit base 11 can form freely an optional pattern as occasion arises by the printing, etc., and on the other hand, the block contact 12 consisting of conductive and elastic material can form each type of point contact, line contact and surface contact, etc., in accordance with the pattern of the resistance circuit. Further, a plunger 13 transmits the external force to the contact 12 accurately in order to bring stably the block contact 12 into contact with the resistance circuit base 11. Then, the contact 12 is in contact with the resistance circuit base 11 in a nonpressure state and the pressure from zero can be detected. Further, since the resistance circuit sets an initial value, it has the stable pressure detecting ability. Moreover, a change of a resistance value is measured only at a contact part between the contact 12 and the resistance circuit and the linear pressure/resistance value characteristic is obtained by determining each shape most suitably and the accurate pressure can be detected.