To improve the visibility of a mail text and a still image or a moving image attached to the mail even when either the still image or the moving image is attached to the mail.

When a still image is attached to a mail, a portable telephone 1a displays a mail text by overlapping it with the still image of 129×96 pixels as a background, and when a moving image is attached to the mail, the portable telephone 1a displays the mail text by placing it beside a moving image reproduced by 96×80 pixels. Also, when the moving image is extended by 129×96 pixels, the portable telephone 1a displays the mail text by overlapping it with the moving image as a background. The expansion system of the moving image may be a system for simply expanding the surrounding of the moving image, a system for linearly increasing an expansion rate according as it goes to the surrounding of the moving image or a system for exponentially increasing the expansion rate according it goes from the central part to surrounding of the moving image.