Provided is an input device using a touch manner. A micro computer and a key control unit perform communications in a serial method to obtain operation stability by reducing the number of data connecting ports between the micro computer and the key control unit. Furthermore, when more than two sets of key matrixes are provided, a plurality of key control unit may be connected to one micro computer to solve interferences between the key patterns. Moreover, operational reliability of the input device using the touch manner is improved by adequately using resources of the key control unit and at the same time reducing processing load of the micro computer.