Abstract: A calibration device for calibrating a gas component analyzing apparatus for analyzing by detecting a component of a sample gas by a detector, which is separated as a single component through a separation unit, wherein the separation unit is connected to a supply tube providing a gas thereto, and a plurality of calibration gases that are adjusted to have different concentrations from each other through adjustment of a volume ratio of a calibration gas having one concentration are sequentially provided to the separation unit through the supply tube.