A portable information processor wherein a menu to be easily used by a user is displayed on a relatively small screen. The portable information processor is provided with an installation section (12) for installing a program; a category information acquiring section (13) which acquires category information displaying a category of a new program upon further installation of the new program; and a category judging section (15) which compares the category of the new program indicated by the category information acquired by the category information acquiring section (13) with categories of a plurality of existing programs and judges whether the category of the new program overlaps any of the categories of the existing programs upon installation of the new program.