A power steering apparatus includes a power cylinder including first and second pressure chambers; a reversible pump including a first outlet port and a second outlet port; a first hydraulic passage including a portion made from an elastomer; a second hydraulic passage including a portion made from an elastomer; a motor arranged to drive the reversible pump; a motor control section; a pump reverse rotation judging section configured to judge a reverse rotation state of the reversible pump when an actual rotation direction of the reversible pump does not correspond to a direction in which the motor is rotated by the driving signal from the motor control section; and a damping torque adding section configured to damp a torque generated in the reversible pump when the pump reverse rotation judging section determines the reverse rotation state of the reversible pump.
