A portable information terminal holding base capable of holding one of a plurality of types of portable information terminals (30, 40) including at least a first portable information terminal and a second portable information terminal having larger length and width sizes than the first portable information terminal, the portable information terminal holding base comprising: a holding base main body having a main mounting surface that is inclined with respect to a horizontal surface and that is wider than a mounting surface of the first portable information terminal; a terminal cover to be fixed to a lower end of the main mounting surface, the terminal cover being configured to support a lower end of the one of the plurality of types of portable information terminals to be held on the main mounting surface; and an extensible holding member provided on a first side edge portion side of the holding base main body, the extensible holding member comprising a slide plate that is slidable inside the holding base main body, the extensible holding member having an extensible mounting surface that is movable in parallel to the main mounting surface, the extensible holding member being capable of holding the second portable information device when the extensible holding member is extended to a predetermined extension position; characterized by a plurality of cradle tabs (14-1 to 14-4) provided on the main mounting surface with apart from each other in an up-and-down direction and in a right-and-left direction, the plurality of cradle tabs being brought into a state of being embedded below the main mounting surface when the plurality of cradle tabs are folded, and being projected above the main mounting surface when the plurality of cradle tabs are raised, thereby being capable of supporting a lower end of the first portable information terminal on the main mounting surface. a holding base main body having a main mounting surface that is inclined with respect to a horizontal surface and that is wider than a mounting surface of the first portable information terminal; a terminal cover to be fixed to a lower end of the main mounting surface, the terminal cover being configured to support a lower end of the one of the plurality of types of portable information terminals to be held on the main mounting surface; and an extensible holding member provided on a first side edge portion side of the holding base main body, the extensible holding member comprising a slide plate that is slidable inside the holding base main body, the extensible holding member having an extensible mounting surface that is movable in parallel to the main mounting surface, the extensible holding member being capable of holding the second portable information device when the extensible holding member is extended to a predetermined extension position; characterized by a plurality of cradle tabs (14-1 to 14-4) provided on the main mounting surface with apart from each other in an up-and-down direction and in a right-and-left direction, the plurality of cradle tabs being brought into a state of being embedded below the main mounting surface when the plurality of cradle tabs are folded, and being projected above the main mounting surface when the plurality of cradle tabs are raised, thereby being capable of supporting a lower end of the first portable information terminal on the main mounting surface.