The present invention relates to a readout circuit for a touch sensor which can increase touch sensing sensitivity regardless of a process variation and a driving voltage of the touch sensor.The readout circuit includes a comparative circuit for setting an input range of a readout signal from the readout line as well as scaling the readout signal to be a required driving range and forwarding the readout signal scaled thus as a touch sensing signal, and an analog to digital converter for converting the touch sensing signal from the comparative circuit as a digital sensing signal and forwarding the digital sensing signal.