PURPOSE: To prepare plural identification number input devices to a single terminal equipment main body by forming the identification number input device in a card shape and reading the identification numbers via a card reader set to the terminal equipment main body.

CONSTITUTION: A user receives a card from a clerk each time and inputs his/her identification number of the prescribed number of digits with operations of keys on a keyboard. Thus only the number of digits of the input identification number is shown at a display part 27 in the asterisks in order to keep the secrecy. When an input/register key 25 is pushed after the input of the prescribed number of digits, the input operation is through with the identification number. The identification number inputted to a card 21 is stored in a specific area of a control part 31 from a keyboard part 26 via a bus 30. An operator receives the card 21 with which the input of the identification number is through and puts the card 21 into the card slit of an IC card reader. Then the identification number stored in the part 31 is read with operation of a terminal equipment main body via an IC card contact 28. The identification number of the card 21 is erased when the number is read into the terminal equipment main body.