The invention relates to a switching matrix for an input device such as a keyboard or a cursor device for the detection of different switching states. According to the invention the switching matrix has a group electrically connected to a microcontroller, with a plurality of N input and output lines (I/O-lines) with a serially connected terminating resistor to mass each and a group with a plurality of K switching lines with one switching element each. Each switching line connects two of the N I/O lines to each other. The K switching line have an additional series resistor each. According to an interrogation pattern, a first I/O-line as output line is configured with a high potential, a second I/O-line is configured as input line and each further I/O-line as output line is configured with a low potential of the microcontroller.