The invention provides an electric power steering apparatus in which a
dead zone is not generated even at a low duty ratio while slow starting a
switching element. When a duty ratio of a PWM control becomes more than a
preset value (NO in S14), a switching cycle is set to a predetermined
value (a fixed value) (S20). When the duty ratio becomes equal to or less
than the preset value (Yes in S14), the switching cycle is made longer
than the predetermined value (S16). It is possible to securely apply a
current to a motor and it is possible to prevent a dead zone from being
generated, by elongating the switching cycle even in a low duty ratio
while slow starting an FET and preventing a noise from being generated.