A controller for a steering device, the steering device including a structure where motive power transmission between a steering unit and a turning unit is separated, the turning unit being configured to turn turning wheels in accordance with steering that is input into a steering wheel coupled with the steering unit, the controller comprising a control circuit configured to control operation of a steering-side motor that is provided in the steering unit so as to give steering reaction force that is force against the steering input into the steering unit, characterized in that: in a case where turning of the turning wheels to one direction is restricted, the control circuit is configured to calculate restriction reaction force for restricting steering that is to turn the turning wheels to the one direction; and the control circuit is configured to calculate the restriction reaction force based on information on the steering unit, wherein the control circuit is configured to store a steering end position that is set closer to a neutral position than a steering limit position of the steering wheel; and the control circuit is configured to calculate the restriction reaction force based on the steering end position and a present steering position of the steering wheel, wherein: the control circuit is configured to set a changed steering end position based on a vehicle speed; and the control circuit is configured to change the steering end position to the set changed steering end position. the controller comprising a control circuit configured to control operation of a steering-side motor that is provided in the steering unit so as to give steering reaction force that is force against the steering input into the steering unit, characterized in that: in a case where turning of the turning wheels to one direction is restricted, the control circuit is configured to calculate restriction reaction force for restricting steering that is to turn the turning wheels to the one direction; and the control circuit is configured to calculate the restriction reaction force based on information on the steering unit, wherein the control circuit is configured to store a steering end position that is set closer to a neutral position than a steering limit position of the steering wheel; and in a case where turning of the turning wheels to one direction is restricted, the control circuit is configured to calculate restriction reaction force for restricting steering that is to turn the turning wheels to the one direction; and the control circuit is configured to calculate the restriction reaction force based on information on the steering unit, wherein the control circuit is configured to store a steering end position that is set closer to a neutral position than a steering limit position of the steering wheel; and the control circuit is configured to calculate the restriction reaction force based on the steering end position and a present steering position of the steering wheel, wherein: the control circuit is configured to set a changed steering end position based on a vehicle speed; and the control circuit is configured to change the steering end position to the set changed steering end position. the control circuit is configured to set a changed steering end position based on a vehicle speed; and the control circuit is configured to change the steering end position to the set changed steering end position.