There is offered a signal processing circuit for an electrostatic capacity type touch sensor capable of detecting a larger number of locations with a smaller number of touch pads as well as improving noise immunity. A selection circuit selects either a signal from a combination of the first and second kinds of touch pads outputted through the first and second output terminals CO1 and CO2 in a touch panel or a signal from a combination of the third and fourth kinds of touch pads outputted through the third and fourth output terminals CO3 and CO4. An electric charge amplifier outputs first and second output voltages V1 and V2 corresponding to a difference between capacitances of the touch pads on the touch panel based on the signals from the selected combination. A delta sigma type A/D converter converts the first and second output voltages V1 and V2 into digital signals.