A pointer detection apparatus, comprising: (a) a conductor pattern including a plurality of first conductors disposed in a first direction and a plurality of second conductors disposed in a second direction which crosses the first direction, wherein one or more of the first conductors are connected to the output of a respective phase inverter (381, 391, 396, 401, 406); (b) a spread code production circuit configured to produce a plurality of modulated signals by modulating a plurality of code strings that are orthogonal to each other, each having the same code string, and to supply the produced plurality of modulated signals to the plurality of first conductors; a reception conductor selection circuit including detection blocks each including a predetermined number of reception conductors, the reception conductor selection circuit comprising a switch adapted to select a reception conductor among said predetermined number of reception conductors included in the detection block, the reception conductor selection circuit being adapted to supply a signal from the selected reception conductor to a signal detection circuit; (c) a signal detection circuit including a differential amplifier (380, 390, 400, 405, 411, 430) whose phase inverting and phase non-inverting input terminals are connected to the plurality of second conductors, wherein the signal detection circuit is configured to receive and demodulate signals from the plurality of second conductors generated in response to the plurality of modulated signals supplied to the plurality of first conductors, and to detect and output a signal corresponding to a variation of capacitance between the conductor pattern and a pointer; (d) an analog to digital conversion circuit configured to convert the signal output from the signal detection circuit into a digital signal comprising a word string formed of a plurality of bits; (e) a correlation detection circuit configured to determine correlation values between the plurality of code strings that are provided for correlation and the word string output from the analog to digital conversion circuit; (f) a memory circuit configured to store the correlation values, each having a plurality of bits successively output from the correlation detection circuit; and (g) a position calculation circuit configured to calculate a position on the conductor pattern pointed to by the pointer based on the correlated values, wherein the spread code production circuit is further configured to supply orthogonal code signals of a same phase difference collectively to first conductors positioned adjacent to each other and to said phase inverters (381, 391, 396, 401, 406), so that the phase of at least one of the orthogonal code signals is inverted by the respective phase inverter (381, 391, 396, 401, 406), wherein the input terminals of the differential amplifier are disposed such that their polarities have the same pattern, in ascending order of the index of the second conductors, as the phases of the orthogonal code signals supplied to the first conductors have in ascending order of the index of the first conductors. (a) a conductor pattern including a plurality of first conductors disposed in a first direction and a plurality of second conductors disposed in a second direction which crosses the first direction, wherein one or more of the first conductors are connected to the output of a respective phase inverter (381, 391, 396, 401, 406); (b) a spread code production circuit configured to produce a plurality of modulated signals by modulating a plurality of code strings that are orthogonal to each other, each having the same code string, and to supply the produced plurality of modulated signals to the plurality of first conductors; a reception conductor selection circuit including detection blocks each including a predetermined number of reception conductors, the reception conductor selection circuit comprising a switch adapted to select a reception conductor among said predetermined number of reception conductors included in the detection block, the reception conductor selection circuit being adapted to supply a signal from the selected reception conductor to a signal detection circuit; (c) a signal detection circuit including a differential amplifier (380, 390, 400, 405, 411, 430) whose phase inverting and phase non-inverting input terminals are connected to the plurality of second conductors, wherein the signal detection circuit is configured to receive and demodulate signals from the plurality of second conductors generated in response to the plurality of modulated signals supplied to the plurality of first conductors, and to detect and output a signal corresponding to a variation of capacitance between the conductor pattern and a pointer; (d) an analog to digital conversion circuit configured to convert the signal output from the signal detection circuit into a digital signal comprising a word string formed of a plurality of bits; (e) a correlation detection circuit configured to determine correlation values between the plurality of code strings that are provided for correlation and the word string output from the analog to digital conversion circuit; (f) a memory circuit configured to store the correlation values, each having a plurality of bits successively output from the correlation detection circuit; and (g) a position calculation circuit configured to calculate a position on the conductor pattern pointed to by the pointer based on the correlated values,