A polishing slurry including an oxidant, a metal oxide dissolver, a metal inhibitor and water and having a pH from 2 to 5. The metal oxide dissolver contains one or more compounds selected from one or more acids (A-group) selected from acids of which the negative value of the logarithm of the dissociation constant Ka (pKa) of a first dissociable acid group is less than 3.7 and from which five acids of lactic acid, phthalic acid, fumaric acid, maleic acid and aminoacetic acid are excluded, ammonium salts of the A-group and esters of the A-group, and one or more compounds selected from one or more acids (B-group) selected from acids of which the negative value of the logarithm of the dissociation constant Ka (pKa) of a first dissociable acid group is 3.7 or more and the five acids, ammonium salts of the B-group and esters of the B-group. The metal inhibitor contains one or more types selected from the group consisting of aromatic compounds having a triazole skeleton and one or more types selected from the group consisting of aliphatic compounds having a triazole skeleton and compounds having any one of pyrimidine skeleton, imidazole skeleton, guanidine skeleton, thiazole skeleton and pyrazole skeleton. The polishing slurry having a high metal-polishing rate, reducing etching rate and polishing friction, results in the production, with high productivity, of semiconductor devices reduced in dishing and erosion in metal wiring.