An internal step-down power supply circuit has an internal step-down power-supply output node, a driver, a divider circuit and a current mirror circuit. A plurality of NMOS transistors are provided on the substrate along the X-axis direction such that a gate length direction of each of the NMOS transistors is parallel to the X-axis direction, and each of the plurality of NMOS transistors is opposed to a corresponding one of the PMOS transistors in the Y-axis direction. The gate electrode has a spacer layer located adjoining a sidewall thereof. A transfer unit circulates the adsorbent between the adsorbing tower and the desorbing tower.