In molding operation, a control device causes an injection device (20) to move forward toward a target position where a nozzle (21a) is in contact with a movable-side mold (4). When the injection device (20) moves forward to a determination position at the rear of the target position, (i) if a fixed-side mold (3) and the movable-side mold (4) are closed, the control device causes the injection device (20) to move further forward to the target position and, (ii) if the fixed-side mold (3) and the movable-side mold (4) are not closed, the control device stops forward movement of the injection device (20) and causes the injection device (20) to move further forward to the target position after the fixed-side mold (3) and the movable-side mold (4) are closed.