An electronically controlled throttle control apparatus prevents a throttle valve from malfunctioning due to deterioration in sliding resistance ascribable to abrasive dust at a sliding contact portion between a valve gear of a geared reduction device and a coil spring. The outer periphery of a spring inner periphery guide is provided with a plurality of groove portions as abrasive dust removing means for removing abrasive dust at least from a sliding contact portion between the outer periphery of the spring inner periphery guide and the inner periphery of a default spring, so that individual edge portions of the plurality of groove portions can rub the inner periphery of the default spring to scrape off abrasive dust from the inner periphery of the default spring and direct the abrasive dust into the plurality of groove portions.