To enable early and accurate confirmation of a read image acquired by an image reading device, at a mobile terminal side.

A multifunctional apparatus 2 executes: a reading processing for reading a manuscript image by an image reading unit 22 to acquire a read image; a partial image generation processing for generating partial image data of an image size having an identical magnification to the read image and corresponding to a display capability of a display unit 33 of a mobile terminal 3; a partial transmission processing for transmitting the partial image data to the mobile terminal by a reading-side communication unit 23; and after the execution thereof, on determining that an overall-image request command is received from the mobile terminal, an overall-transmission processing for transmitting the overall read image data to the mobile terminal.