A control method of a washing machine including a wireless communicator communicating with an electronic device, includes: causing the washing machine to operate a washing tub of the washing machine as a preliminary operation, including a rotational operation of the washing tub; acquiring motion information regarding a motion of the electronic device during the preliminary operation; determining whether or not the electronic device is inside the washing tub based on the acquired motion information and information indicating the preliminary operation; and giving the washing machine a notification indicating that the electronic device is inside the washing tub if the determining determines that the electronic device is inside the washing tub. It is determined whether or not the electronic device is inside the washing tub, based on a comparison between characteristic operation information determined in advance with regard to the preliminary operation and the motion information acquired by a sensor.