A driver assistance device configured to perform deceleration assistance control when a driver of a vehicle is not depressing an accelerator pedal, the deceleration assistance control being control for automatically decelerating the vehicle, the driver assistance device comprising: a detection unit configured to detect an operation of the accelerator pedal; and a control unit configured to cancel the deceleration assistance control when the operation of the accelerator pedal is detected during the deceleration assistance control, wherein the control unit is configured to reduce a deceleration control amount for the deceleration assistance control according to a degree of the operation of the accelerator pedal, when cancelling the deceleration assistance control; characterized in that the control unit is configured to: determine target acceleration for the vehicle based on the deceleration control amount and requested acceleration from the driver that is estimated from the operation of the accelerator pedal, when canceling the deceleration assistance control; determine the target acceleration such that a change in the target acceleration with time corresponds to a change in the deceleration control amount with time, when the target acceleration is smaller than the requested acceleration; and determine the target acceleration such that the change in the target acceleration with time corresponds to a change in the requested acceleration with time, when the target acceleration reaches the requested acceleration. a detection unit configured to detect an operation of the accelerator pedal; and a control unit configured to cancel the deceleration assistance control when the operation of the accelerator pedal is detected during the deceleration assistance control, wherein the control unit is configured to reduce a deceleration control amount for the deceleration assistance control according to a degree of the operation of the accelerator pedal, when cancelling the deceleration assistance control; characterized in that the control unit is configured to: determine target acceleration for the vehicle based on the deceleration control amount and requested acceleration from the driver that is estimated from the operation of the accelerator pedal, when canceling the deceleration assistance control; determine the target acceleration such that a change in the target acceleration with time corresponds to a change in the deceleration control amount with time, when the target acceleration is smaller than the requested acceleration; and determine the target acceleration such that the change in the target acceleration with time corresponds to a change in the requested acceleration with time, when the target acceleration reaches the requested acceleration. determine target acceleration for the vehicle based on the deceleration control amount and requested acceleration from the driver that is estimated from the operation of the accelerator pedal, when canceling the deceleration assistance control; determine the target acceleration such that a change in the target acceleration with time corresponds to a change in the deceleration control amount with time, when the target acceleration is smaller than the requested acceleration; and determine the target acceleration such that the change in the target acceleration with time corresponds to a change in the requested acceleration with time, when the target acceleration reaches the requested acceleration.