An automatic driving system includes an electronic control device configured to: detect a driving operation input amount during an automatic driving control for a vehicle; determine whether the driver is able to start manual driving during the automatic driving control for the vehicle; output a signal for performing switching from automatic driving to the manual driving based on a result of a comparison between the driving operation input amount and a driving switching threshold that is a threshold for the switching from the automatic driving to the manual driving; set the driving switching threshold to a first driving switching threshold when it is determined that the driver is able to start the manual driving; and set the driving switching threshold to a second driving switching threshold exceeding the first driving switching threshold when it is determined that the driver is not able to start the manual driving.