A capacitance detection device includes a sensor unit including at least one sensor element whose capacitance changes, a control line applying to the sensor element a predetermined charging voltage for detecting the capacitance of the sensor element, a shield line electrically shielding the control line, a control circuit supplying the charging voltage to the sensor element via the control line, measuring a voltage change of the sensor element when the charging voltage is applied to the sensor element, and detecting the capacitance of the sensor element based on the voltage change, and an equipotential circuit setting a potential of the shield line equal to a potential of the control line.