To facilitate tile cleansing on the surface of constructions and lowers the resoiling of the tiles.

This tile-cleansing agent comprises a mixed aqueous solution of ammonium fluoride and a hydroxylated organic acid or a mixed aqueous solution of ammonium fluoride, a hydroxylated organic acid and a glycol solvent. Further, an inorganic acid or organic acid (except the hydroxylated organic acids) are added thereto in order to increase its cleansing properties, in addition, one or two or more kinds of vegetable oils or its derivatives, animal oils or its derivatives may be added thereto. Further, tiles on wall faces or floor faces are coated with the cleansing agent on their surfaces to separate the soil and stain on the tile surfaces and they are wiped off whereby the whole concentration of the acid can be set lower than 20% and ≤3 mol/l and the pH can be set to ≥3.