A seat belt device comprising: a belt reel around which webbing, which restrains a passenger who sits in a seat, is wound; a winding spring that rotationally biases the belt reel in a winding direction; a motor that is configured to transmit a driving force to the belt reel; and a clutch that is interposed between the motor and the belt reel, and that performs connection and disconnection between the motor and the belt reel, wherein, in a state in which the clutch is connected, the motor side and the belt reel side rotate integrally only in a case where a rotational speed in the winding direction on the motor side is greater than or equal to the rotational speed on the belt reel side, and free rotation of the belt reel side is allowed by sliding components mutually in a case in which the rotational speed in the winding direction on the belt reel side is greater than the rotational speed on the motor side, and wherein the seat belt device further includes a webbing speed detection unit (11; 21) that detects a winding speed of the webbing; a fastened/released state detection unit that detects a fastened state and a released state of the webbing that are due to an operation of the passenger; a basic winding control unit that drives the motor in the winding direction in a rotating manner and puts the clutch into a connected state when a result detected by the fastened/released state detection unit is switched from the fastened state to the released state; characterized in that the seat belt device further includes a speed increase correction unit that increases the speed of the motor with respect to the speed of the motor that is obtained by the control of the basic winding control unit in a case in which a result detected by the fastened/released state detection unit has been switched from the fastened state to the released state and the winding speed of the webbing that is detected by the webbing speed detection unit (11; 21) is greater than or equal to a predetermined speed. a belt reel around which webbing, which restrains a passenger who sits in a seat, is wound; a winding spring that rotationally biases the belt reel in a winding direction; a motor that is configured to transmit a driving force to the belt reel; and a clutch that is interposed between the motor and the belt reel, and that performs connection and disconnection between the motor and the belt reel, wherein, in a state in which the clutch is connected, the motor side and the belt reel side rotate integrally only in a case where a rotational speed in the winding direction on the motor side is greater than or equal to the rotational speed on the belt reel side, and free rotation of the belt reel side is allowed by sliding components mutually in a case in which the rotational speed in the winding direction on the belt reel side is greater than the rotational speed on the motor side, and wherein the seat belt device further includes a webbing speed detection unit (11; 21) that detects a winding speed of the webbing; a fastened/released state detection unit that detects a fastened state and a released state of the webbing that are due to an operation of the passenger; a basic winding control unit that drives the motor in the winding direction in a rotating manner and puts the clutch into a connected state when a result detected by the fastened/released state detection unit is switched from the fastened state to the released state; characterized in that the seat belt device further includes a speed increase correction unit that increases the speed of the motor with respect to the speed of the motor that is obtained by the control of the basic winding control unit in a case in which a result detected by the fastened/released state detection unit has been switched from the fastened state to the released state and the winding speed of the webbing that is detected by the webbing speed detection unit (11; 21) is greater than or equal to a predetermined speed.