A capacitive stylus pen is provided that inputs an indicated position to a tablet by capacitive coupling. The capacitive stylus pen includes a signal generating circuit that generates a signal having the same frequency as a frequency of a signal to be transmitted from an electrode, a transformer that boosts the generated signal and that includes a primary winding and a secondary winding, and an analog switch for controlling connection between a first end of the secondary winding and the electrode to an on-state or an off-state. The capacitive stylus pen further includes a power extracting circuit that extracts power to be supplied to the analog switch from an electromotive force induced in the secondary winding, and a capacitor coupled to a second end of the secondary winding to set the second end at a fixed potential in an alternating-current manner.