A sampling unit acquires a sample data series of a signal indicating a touch state quantity detected in a touch panel. A discrete Fourier transformation unit transforms the sample data series into the frequency domain. The frequency spectral analysis unit determines a frequency spectral distribution in accordance with the sample data transformed into the frequency domain. A peak detection unit detects a peak in a frequency band of a pulse in the frequency spectral distribution and finds the frequency of the detected peak so as to determine the pulse.
