PURPOSE: To make it possible to use an electronic computer as an identification card by providing a discriminating means which generates a new signal in response to the input from an external connection terminal and outputs this signal from the external connection terminal in addition to a calculating means.

CONSTITUTION: The calculating means which performs the calculation processing in a main operating part 7 on the basis of numeric information inputted from a key input part 4 and the discriminating means which generates a new signal in response to the input from the external connection terminal 6 are provided. For example, a card type electronic computer body 1 having a solar cell 2, a display part 3, a key input part 4, etc. is provided with not only the external connection terminal 6 but also a switching key 5 for switching between the calculation mode and the discrimination mode where the electronic computer is operated as the identification card.