PURPOSE: To improve the detection precision for the accelerator opening-degree by installing a resistance variation type pressure sensitive electric conductive rubber member onto an accelerator pedal and controlling an indication lamp and a throttle-valve control circuit by using the electric signals obtained between the terminals of the rubber member.

CONSTITUTION: A compression member 7 made of soft rubber, etc. and an electric conductive member S are installed between an accelerating pedal 2 and a chassis 1. When said rubber member S is applied with a pressure, the resistance value reduced linearly. The electric signals are taken out of the prescribed terminals (a) and (b) of the rubber member S and sent into an indication body or a throttle-valve control circuit. Therefore, the opening degree of an accelerator can be detected with high precision.