To solve the problem that inputting a logical address of URL or the like on a portable telephone or the like takes much time.

A first address acquiring part 50 acquires an official logical address to convert it into a temporary logical address which a conversion part 52 can describe only with numeric keys, and registers the temporary logical address with an address table 46. A character in each digit of the official address is converted into a number assigned to the same key for the character. When a user inputs a temporary logical address, a second address acquiring part 40 receives it, a search part 44 searches the address table 46, and the corresponding official logical address is obtained.