To provide a power steering device capable of stabilizing a behavior of a vehicle by properly controlling steering torque at all times without applying a sense of incongruity to a driver.

A basic steering torque T0 is calculated according to the steering torque Tsw by the steering operation of the driver and a vehicle speed V. According to lateral acceleration d2y/dt2 and the vehicle speed V, a target yaw rate tgt is calculated by an equation of the motion of the vehicle including a secondary transfer function obtained by simulating a response of a yaw rate to the lateral acceleration d2y/dt2. Correction steering torque Ta obtained from deviation between a target yaw rate tgt and the actual yaw rate is added to the basic steering torque T0, and steering torque control is performed based on the steering toque T to which the correction torque is added.