PURPOSE: To improve the efficiency by inputting and outputting bar-code data by the smaller number of bits than a conventional one.

CONSTITUTION: A bar-code is scanned, and fetched binarized data 1 is converted to continuous BCD(binary-coded decimal) code data by a car-code analyzing part 2, and written in a dedicated interface storage part 5. An external apparatus 6 such as a PLC(programmable logic controller), etc., inputs or outputs the contents of the dedicated interface storage part 5 in accordance with constituting information 4 through a dedicated interface circuit 3. The constituting information 4 selects one of an output only and an input and an output when it is looked at from a bar-code reader, and also, selecrs one of 16 words, 8 words and 4 words, and switches, them. When the same digit number, by inputting and outputting the bar-code data by the BCD code, the dedicated interface storage area decreases, therefore, the number of words can be decreased by the constituting information, and a communication speed can be shortened.