An automatic parking system instructs a plurality of autonomous driving vehicles in a parking lot such that each autonomous driving vehicle parks in a target parking space within the parking lot, and includes an instruction change target vehicle specifying unit configured to, in a case where the autonomous driving vehicle becomes a failed vehicle due to abnormality or communication interruption during automatic driving according to instruction, specify an instruction change target vehicle from normal autonomous driving vehicles based on parking lot map information, a location of the failed vehicle, and a location of the normal autonomous driving vehicles, and a vehicle instruction unit configured to, in a case where the instruction change target vehicle is specified, issue a route change instruction, an evacuation instruction, or a stop instruction to the instruction change target vehicle, such that the instruction change target vehicle gets away from the failed vehicle.