A key scan type input device includes a microcomputer having a plurality of output ports for outputting scan signals and a plurality of input ports for receiving key signals in a scan signal section, a first key matrix having a plurality of system control keys arranged in a x*y arrangement, lines of the keys being connected to the respective output ports of the microcomputer and columns of the keys being connected to the respective input ports, and a second key matrix having one or more system control keys arranged in a m*m arrangement, lines and columns being connected in parallel at least two of the output ports and at least two input ports of the microcomputer.