Electronic device is linked with a mobile terminal, screen transition of the electronic device is eliminated, and various operation input is performed while confirming operation content from the mobile terminal on a screen of the electronic device. When proximity of the mobile terminal is detected in a state of displaying a specific screen on an operation display portion, an image forming apparatus transmits operation input information associated with the specific screen in advance to the mobile terminal. The mobile terminal displays an operation input screen based on the operation input information transmitted from the image forming apparatus and transmits operation content instructed by a user from the operation input screen to the image forming apparatus. The image forming apparatus updates the specific screen in accordance with the operation content transmitted from the mobile terminal.