PURPOSE: To effectively utilize a memory by preventing the same dial number from being superposed in an area storing the dial number of a dial number memory part.

CONSTITUTION: A memory control part 3 receives a transmission dial number from a dial button dipressing part 1, temporarily stores it, investigates the storage areas (1) to (3) of the dial number memory part 2 and investigates the presence/absence of the storage of the same number first. When the same number is present thereon, the same number in the storage areas (1) to (3) is erased, the remaining numbers are moved to the storage area of the old number and the number being temporarily-stored is moved to the stoage area of the young number so as to be stored. A memory calling part 4 temporarily stores the dial number received from the memory control part 3 to store it in a display part 5 and, on the other hand, sends the storing dial number to an automatic transmission part 6 at the time of being driven by the automatic transmission part 6, which automatically transmits the dial number received by requiring to the memory calling part 4 to a communication channel.