PURPOSE: To secure the free selection for the division scale of the input items into the size of the integer-fold value as large as the minimum division by giving the selective driving to the drive/sense line of the paired combination of the predetermined driving line selection circuit and the sense line selection circuit.

CONSTITUTION: Driving source 21 and 22 are constituted with current sources the phases of which differ by 180° from each other. Selection control circuit 23 gives an access to driving sense line selection memory circuit 24 to read out the information of the line to be selected. The information is then decoded to select two pairs among the line groups of driving lines lD1,lD2...lDm and sense lines lS1, lS2...lSn via driving line selection circuit 25 and sense line selection circuit 26. Threshold level discrimination circuit 18 detects via the electromagnetic inductive electromotive force induced by sense amplifier 15 the fact that input pen 16 holding the magnetic substance at its tip is indicating the tablet surface. And code generation circuit 27 generates the code corresponding to the position of the input pen.