An electric power steering apparatus includes a booster circuit and a
microcomputer. The booster circuit includes a booster coil, a first FET,
and a second FET. The booster coil is connected to the first FET, which
is grounded. A node a between the booster coil and the first FET is
connected to the second FET, which is connected to a drive circuit. The
microcomputer drives the first and second FETs such that the first and
second FETs are selectively turned on and off, thereby controlling an
output voltage of the booster circuit. When application of assisting
force to a steering system is stopped, the microcomputer holds the second
FETs on until the output voltage of the booster circuit becomes equal to
a predetermined voltage.