A power steering device capable of improving both operability of a vehicle and a feeling of the steering. The power steering device includes an association mechanism for mechanically associating a handle with wheels, a power cylinder for generating assisting force, and a control valve connected to the power cylinder and adapted to be changed over depending on torque inputted thereto from the handle and kept at a neutral position unless the torque is inputted thereto. The control valve functions to control the amount of fluid fed to the power cylinder when it is changed over and close a cylinder port connected to the power cylinder when it is at the neutral position.