An input system, comprising: a touch sensor panel comprising first channels (10, 210) and second channels (20, 220) crossing each other and being capacitance-type electrodes of the touch sensor panel; a touch controller connected to the first channels (10, 210) and second channels (20, 220); a stylus pen; and a stylus ground connected to the stylus pen; wherein a frame period, in which both a stylus and a finger touch detection are performed, is divided, according to time division, into a stylus touch detecting frame period and a finger touch detecting frame period; and wherein each of the first channels (10, 210) and second channels (20, 220) is configured to be driven during the stylus touch detecting frame period; characterized in that: the input system is further comprising: an antenna loop formed in an outer region of the touch sensor panel and connected to the touch controller; and the stylus pen is comprising: a first coil and a second coil divided from each other and inductively coupled by mutual inductance; a conductive tip connected to the first coil; and a resonance capacitor and a switch serially connected to the second coil; wherein the switch is operated by pressure applied to the conductive tip, and wherein, when the stylus pen touches the touch sensor panel, the switch is closed and the second coil and the resonance capacitor form a closed circuit. a touch sensor panel comprising first channels (10, 210) and second channels (20, 220) crossing each other and being capacitance-type electrodes of the touch sensor panel; a touch controller connected to the first channels (10, 210) and second channels (20, 220); a stylus pen; and a stylus ground connected to the stylus pen; wherein a frame period, in which both a stylus and a finger touch detection are performed, is divided, according to time division, into a stylus touch detecting frame period and a finger touch detecting frame period; and wherein each of the first channels (10, 210) and second channels (20, 220) is configured to be driven during the stylus touch detecting frame period; characterized in that: the input system is further comprising: an antenna loop formed in an outer region of the touch sensor panel and connected to the touch controller; and the stylus pen is comprising: a first coil and a second coil divided from each other and inductively coupled by mutual inductance; a conductive tip connected to the first coil; and a resonance capacitor and a switch serially connected to the second coil; wherein the switch is operated by pressure applied to the conductive tip, and wherein, when the stylus pen touches the touch sensor panel, the switch is closed and the second coil and the resonance capacitor form a closed circuit. an antenna loop formed in an outer region of the touch sensor panel and connected to the touch controller; and the stylus pen is comprising: a first coil and a second coil divided from each other and inductively coupled by mutual inductance; a conductive tip connected to the first coil; and a resonance capacitor and a switch serially connected to the second coil; wherein the switch is operated by pressure applied to the conductive tip, and wherein, when the stylus pen touches the touch sensor panel, the switch is closed and the second coil and the resonance capacitor form a closed circuit. a first coil and a second coil divided from each other and inductively coupled by mutual inductance; a conductive tip connected to the first coil; and a resonance capacitor and a switch serially connected to the second coil; wherein the switch is operated by pressure applied to the conductive tip, and wherein, when the stylus pen touches the touch sensor panel, the switch is closed and the second coil and the resonance capacitor form a closed circuit.