Provided are a cleaner composition that can exhibit excellent cleaning ability by including a predetermined amount of water, and can also effectively suppress metal corrosion; and a cleaning method thereof. Disclosed is a cleaner composition in a white turbid state including first to fourth organic solvents and water, in which the first organic solvent is a hydrophobic aromatic compound or the like; the second organic solvent is a hydrophobic monoalcohol compound; the third organic solvent is a predetermined hydrophilic nitrogen-containing compound or the like; the fourth organic solvent is a hydrophilic amine compound; the amount of incorporation of water is adjusted to a value within the range of 50 to 3,900 pbw with respect to 100 pbw of the total amount of the organic solvents, and when the cleaner composition is subjected to phase separation, the water concentration in the oil phase is adjusted to a value of 5 wt. % or less.