The present invention provides a touch sensor system which is capable of removing a hand-placing signal while mounting normal application software on a host device. A touch sensor system (1) includes a hand-placing removing process section (2) which detects a hand-placing region on a basis of strengths of capacitance signals, each strength being indicative of a change in capacitance and which replaces values of capacitance signals corresponding to respective capacitors provided in the detected hand-placing region with a nil value indicative of a state where not touch input is made.