A capacitance measurement device includes a charging control unit for charging a measured capacitor, a discharging control unit for discharging the measured capacitor, a first switch coupled to the measured capacitor and the charging control unit for controlling a connection between the measured capacitor and the charging control unit according to a first switching signal, a second switch coupled to the measured capacitor and the discharging control unit for controlling a connection between the measured capacitor and the discharging control unit according to a second switching signal, a first A/D converter coupled to the measured capacitor for converting a voltage signal on the measured capacitor into a first signal, and a duty cycle detecting circuit coupled to the measured capacitor for converting the voltage signal on the measured capacitor into a count value that represents the capacitance of the measured capacitor and outputting the count value to a processing unit.