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.

Process for cleaning soiled metal surfaces characterized in such cleaning is carried out using a composition that comprises at least one alkoxylated polyethylenimine (B) with a polydispersity Q=M.sub.w/M.sub.n of at least 3.5 and an average molecular weight M.sub.w in the range of from 2,500 to 1,500,000 g/mol.

Described is a method for removing rust from a rusted surface comprising the steps of a) applying to the said surface a first composition comprising a penetrating oil, and b) applying to the said surface a second composition comprising at least one thiol compound, the thiol compound being a thiol substituted carboxylic acid, or a salt or alkyl ester thereof, wherein step b) is carried out prior to, or subsequent, to step a), a kit comprising said first and second compositions, a composition and also to the use of said composition for rust removal.

Described is a method for removing rust from a rusted surface comprising the steps of a) applying to the said surface a first composition comprising a penetrating oil, and b) applying to the said surface a second composition comprising at least one thiol compound, the thiol compound being a thiol substituted carboxylic acid, or a salt or alkyl ester thereof, wherein step b) is carried out prior to, or subsequent, to step a), a kit comprising said first and second compositions, a composition and also to the use of said composition for rust removal.