To give a superior guidance for a purchase of a train ticket and to easily recognize the position of an enlargement frame on the entire map part with retrieval support lines by setting the retrieval adjoint lines around the enlargement frame along an (x) and a (y) axis.

On the entire map part 4c, the retrieval adjoint lines 4d1 and 4d2 in the X-axial direction (horizontal direction) and Y-axial direction (vertical direction) are displayed around display-enlarged 4d. Then a user searches the entire map part 4c for a station L and presses the station L, and the enlargement frame 4d surround the station L is displayed moving from a station A to the station L, so that an enlarged map including the station L in the center is displayed on a enlarged map part 4b (b)-(d). When the enlargement frame 4d further moves, the retrieval adjoint lines 4d1 and 4d2 also move. Consequently, those adjoint lines 4d1 and 4d2 show to the user which position of the entire map part 4c the enlargement frame 4d is present at in an easy-to-understand way.