In the invention, highly pure crystals of difructose dianhydride III (di-D-fructofuranose-1,2':2,3 '-dianhydride; hereinafter referred to as DFA III) are produced by adding 5% or less of powdered active carbon to a DFA III containing purified solution containing DFA III of 90% or more purity at a concentration of R-Bx 10-60, preferably 40-55, and after stirring, applying the mixture to solid-liquid separation (filtration with diatomaceous, filtration through a membrane filter, ultrafiltration, or continuous centrifugal separation) and concentrating the separated liquid part, followed by immediate crystallization. In the process of the invention, DFA III crystals can be produced efficiently and industrially, and the resulting crystals can be used for various purposes in pharmaceuticals or food and drink since they have no smell. This is characteristics of the invention different from the prior art products.