A carbon dioxide capture apparatus comprising: an absorber configured to cause carbon dioxide contained in exhaust gas to be absorbed in an absorbing liquid; a stripper configured to cause the carbon dioxide to be released from the absorbing liquid, supplied from the absorber, containing the absorbed carbon dioxide, the stripper being configured to discharge carbon dioxide-containing gas; an absorber level gauge configured to measure liquid level of the absorbing liquid within the absorber; a first cooler configured to cool the carbon dioxide-containing gas discharged from the stripper and generate first condensed water; a first gas-liquid separator configured to separate the first condensed water generated by the first cooler from the carbon dioxide-containing gas; a compressor configured to compress the carbon dioxide-containing gas discharged from the first gas-liquid separator; a second cooler configured to cool the carbon dioxide-containing gas discharged from the compressor and generate second condensed water; a second gas-liquid separator configured to separate the second condensed water generated by the second cooler from the carbon dioxide-containing gas; a washing unit arranged on the upper portion of the absorber and configured to use cleaning water to clean the exhaust gas from which the carbon dioxide is absorbed in the absorbing liquid; a regulating liquid tank configured to store a regulating liquid that contains water, the regulating liquid used to control a proportion of water contained in the absorbing liquid; a regulating liquid control valve configured to control flow rate of the regulating liquid to be supplied by a regulating liquid supply driving unit from the regulating liquid tank to the absorber or the stripper; and a controller configured to control the opening degree of the regulating liquid control valve based on the liquid level of the absorbing liquid measured by the absorber level gauge, wherein the first condensed water, and at least one of the second condensed water and the cleaning water are collected as the regulating liquid in the regulating liquid tank. an absorber configured to cause carbon dioxide contained in exhaust gas to be absorbed in an absorbing liquid; a stripper configured to cause the carbon dioxide to be released from the absorbing liquid, supplied from the absorber, containing the absorbed carbon dioxide, the stripper being configured to discharge carbon dioxide-containing gas; an absorber level gauge configured to measure liquid level of the absorbing liquid within the absorber; a first cooler configured to cool the carbon dioxide-containing gas discharged from the stripper and generate first condensed water; a first gas-liquid separator configured to separate the first condensed water generated by the first cooler from the carbon dioxide-containing gas; a compressor configured to compress the carbon dioxide-containing gas discharged from the first gas-liquid separator; a second cooler configured to cool the carbon dioxide-containing gas discharged from the compressor and generate second condensed water; a second gas-liquid separator configured to separate the second condensed water generated by the second cooler from the carbon dioxide-containing gas; a washing unit arranged on the upper portion of the absorber and configured to use cleaning water to clean the exhaust gas from which the carbon dioxide is absorbed in the absorbing liquid; a regulating liquid tank configured to store a regulating liquid that contains water, the regulating liquid used to control a proportion of water contained in the absorbing liquid; a regulating liquid control valve configured to control flow rate of the regulating liquid to be supplied by a regulating liquid supply driving unit from the regulating liquid tank to the absorber or the stripper; and a controller configured to control the opening degree of the regulating liquid control valve based on the liquid level of the absorbing liquid measured by the absorber level gauge, wherein the first condensed water, and at least one of the second condensed water and the cleaning water are collected as the regulating liquid in the regulating liquid tank.