A headrest apparatus comprising a headrest rear portion supported at a seatback, a headrest front portion movable between a fully retracted position and a fully expanded position, a driving means moving the headrest front portion, an capacitance sensor outputting a detection signal representing an capacitance, a controller moving the headrest front portion toward the fully expanded position and controlling the driving means to stop the headrest front portion, a load sensor detecting a load applied to the headrest front portion, and the controller judging a completion of a protection of the head of the occupant on the basis of the load detected by the load sensor in a condition where the headrest front portion is stopped and controlling the driving means to move the headrest front portion toward the fully retracted position when a completion of the protection of the head of the occupant is determined.