INPUT DEVICE

PROBLEM TO BE SOLVED: To provide an input device without providing any special hardware for imparting identification information of plural input devices then without increasing its cost. SOLUTION: In this input device for an information processing system to be constituted as so to identify the input device by an ID code, for example, by providing the information processing system with one or two or more computer main bodies and plural input devices and imparting an intrinsic ID code for every input device, the ID code is imparted based on initial operation timing and initially inputted information after start of input operation of each input device. For example, when the input device is a keyboard 10 provided with a key input means, the ID code is generated by using three pieces of data such as an elapsed time (S16) up to the first key on after the start of the input operation, an elapsed time (S22) up to further key off of the key which is depressed on and a key code of the key which is depressed.