A drive supporting device includes a supporting device mounted on a vehicle and capable of executing driving support in the vehicle; a steering angle detecting device configured to detect a steering angle of a steering member of the vehicle; a torque detecting device configured to detect a torque acting on a steering shaft portion that rotates with the steering member; and a controller configured to control the supporting device, wherein the controller changes content of the driving support by the supporting device between a case in which a steering power corresponding to a product of a parameter associated with the steering angle detected by the steering angle detecting device and a parameter associated with the torque detected by the torque detecting device is greater than or equal to a reference value set in advance, and a case in which the steering power is smaller than the reference value.