An aromatic polysulfone comprising an aromatic polysulfone having at least one highly polar functional group at its terminal, which comprises 80 mol% or more and 100 mol% or less of a repeating unit represented by a formula with respect to the total amount of all the repeating units constituting the aromatic polysulfone, -Ph 1 -SO 2 -Ph 2 -O- wherein Ph 1 and Ph 2 each independently represent a phenylene group, and one or more hydrogen atoms in said phenylene group may be each independently substituted with an alkyl group, an aryl group or a halogen atom, wherein the highly polar functional group is a polar functional group having an acid dissociation constant smaller than that of a carboxyl group, and wherein in said aromatic polysulfone, the ratio of the aromatic polysulfone having a highly polar functional group with respect to the combined total of all the aromatic polysulfones is 19% by mass or more and 100% by mass or less, wherein an area of a signal attributed to said aromatic polysulfone having a highly polar functional group with respect to a total area of all signals attributed to said aromatic polysulfone in a chromatogram obtained by measurement through a gel permeation chromatography method under the following conditions is 19% or more and 100% or less, [Conditions] Sample injection volume: 5 μL Column: "Shodex KF-803" manufactured by Showa Denko K.K. Column temperature: 40°C Eluent: N,N-dimethylformamide Eluent flow rate: 0.5 mL/min Detector: ultraviolet-visible spectrophotometer (UV) Detection wavelength: 277 nm. which comprises 80 mol% or more and 100 mol% or less of a repeating unit represented by a formula with respect to the total amount of all the repeating units constituting the aromatic polysulfone, -Ph 1 -SO 2 -Ph 2 -O- wherein Ph 1 and Ph 2 each independently represent a phenylene group, and one or more hydrogen atoms in said phenylene group may be each independently substituted with an alkyl group, an aryl group or a halogen atom, wherein the highly polar functional group is a polar functional group having an acid dissociation constant smaller than that of a carboxyl group, and wherein in said aromatic polysulfone, the ratio of the aromatic polysulfone having a highly polar functional group with respect to the combined total of all the aromatic polysulfones is 19% by mass or more and 100% by mass or less, wherein an area of a signal attributed to said aromatic polysulfone having a highly polar functional group with respect to a total area of all signals attributed to said aromatic polysulfone in a chromatogram obtained by measurement through a gel permeation chromatography method under the following conditions is 19% or more and 100% or less, [Conditions] Sample injection volume: 5 μL Column: "Shodex KF-803" manufactured by Showa Denko K.K. Column temperature: 40°C Eluent: N,N-dimethylformamide Eluent flow rate: 0.5 mL/min Detector: ultraviolet-visible spectrophotometer (UV) Detection wavelength: 277 nm. Sample injection volume: 5 μL Column: "Shodex KF-803" manufactured by Showa Denko K.K. Column temperature: 40°C Eluent: N,N-dimethylformamide Eluent flow rate: 0.5 mL/min Detector: ultraviolet-visible spectrophotometer (UV) Detection wavelength: 277 nm. <EOS>