Provided is an information acquisition method in an information acquisition system including an information device possessed by a user. A detecting step detects a specific action performed by the user while driving a motor vehicle. A first saving step acquires and saves, in a storage unit, motor vehicle position information indicating a position of the motor vehicle if the specific action is detected by the detecting step. A deleting step deletes the motor vehicle position information from the storage unit in a case in which the specific action is an action other than an action of speaking a voice phrase, and when a designated time elapses in a case in which the user does not perform an action of speaking a voice phrase from a time at which the specific action was detected and before the designated time elapses.