PURPOSE: To reduce the load of the device like an external computer, etc. and shorten the processing time of a data input device, by setting a data processor into a keyboard and delivering the data supplied with operation of a key to outside after applying the prescribed processing to said data.

CONSTITUTION: The code data on the numeric characters and characters are delivered from a keyboard 20 with operations of numeric character keys and character keys on the keyboard 20. Then the code data is fetched temporarily in a data processor 22 and then stored temporarily in a buffer memory 21. The processor 22 reads the data out of the memory 21 and applies the prescribed processing this data such as the conversion processing of character code or the simple numerical calculation processing. The result of this processing is supplied to an external computer 1. Thus the computer 1 can proceed immediately to the data processing at a new processing level without the conversion processing of character code.