In an electric throttle-control apparatus for controlling an open position of a throttle valve 6 connected to reduction gears 47 to reduce rotational speed of the motor 4, by driving a motor 4 which includes a commutator 32 with a plurality of slots 44, and brushes 31 and 31′, the number of the slots in the commutator and the arrangement of brushes on the slots are set such that even and odd number slot states appear alternately in an electrical equivalent-circuit of a wire-connection among slots including the brushes while the motor rotates. Further, if the number of the slots 44 is the odd number 9, 11, or 13, the brushes 31 and 31′ are arranged in a 180° opposed placement, and if the number of the slots 44 is the even number 10 or 12, the brushes 31 and 31′ are arranged in a non-opposed placement shifted from a 180° opposed placement.