The polishing apparatus comprises: a dressing section for dressing a polishing pad; a measuring section for measuring a surface property of the polishing pad; a polishing result measuring section for measuring a polishing result of a work; a storing section for storing correlation data between dressing condition data for dressing the polishing pad, surface property of the polishing pad and polishing results, which are learned by an artificial intelligence; and an input section for inputting an object polishing result. The artificial intelligence performs a first arithmetic process, in which the surface property of the polishing pad corresponding to the object polishing result is inversely estimated on the basis of the correlation data, and a second arithmetic process, in which the corresponding dressing condition is derived on the basis of the surface property of the polishing pad inversely estimated.