TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The electrolyte solution is used in secondary battery having cathode containing active material consisting of silicon, tin and/or lead, or carbonaceous material.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compounds: The carbonate having halogen atom is cyclic carbonate or linear carbonate. The carbonate is contained in an amount of 0.001-100 mass%, preferably 0.001-10 mass% with respect to the non-aqueous solvent. The mono-fluorophosphoric acid salt and/or difluorophosphate is contained in an amount of 0.001-5 mass% with respect to the whole electrolyte solution. The electrolyte solution is a liquid at 25 degrees C and has dielectric constant of 5 or more and viscosity coefficient of 0.6 cP or less, and further contains compound having skeleton containing hetero atom or compound having ether skeleton and/or nitrile skeleton, 0.01-25 mass% of lactone compound, compound having substituent and carbon-carbon triple bond, nitrile compound, isocyanate compound, phosphazene compound, disulfonic acid ester compound, sulfide compound, disulfide compound and/or acid anhydride. The compound having skeleton containing hetero atom has halogenated group and/or saturated aliphatic hydrocarbon substituent without any substituents other than halogen. The mono-fluorophosphoric acid salt and/or difluorophosphate is of formula: R1-P(=O)(R2)-R3 (1).R1-R3=fluorine, 1-12C alkyl optionally substituted with fluorine or 1-12C alkoxy optionally substituted with fluorine.Alternately, the electrolyte solution contains 10-70 volume% of cyclic sulfone compound, compound (30-90 volume%) having viscosity coefficient of 1.5 mPa.second or less at 25 degrees C and compound (0.001-8 mass%) chosen from carbonate (a) having unsaturated bond, carbonate (b) having halogen atom, mono-fluorophosphoric acid salt and difluorophosphate. The cyclic sulfone compound is sulfolane and/or its derivative(s). The compound having viscosity coefficient of 1.5 mPa.second or less is linear carbonate, chain-shaped carboxylate ester, chain-shaped ether or cyclic ether, preferably dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl acetate, methyl propionate, methyl butyrate or 1,2-dimethoxy ethane. The carbonate (a) is vinylene carbonate or vinyl ethylene carbonate, the carbonate (b) is fluorinated ethylene carbonate, fluorinated dimethyl carbonate, fluorinated diethyl carbonate or fluorinated ethyl methyl carbonate. Alternately, the electrolyte solution contains 0.001-0.5 mol/l of cyclic disulfonyl imide salt of formula (i) with respect to the electrolyte solution, and mono-fluorophosphoric acid salt and difluorophosphate.R=1-12C (fluoro)alkylene group further substituted by (fluoro)alkyl;M=n valent metal of group 1, 2, 13 or quaternary onium;andn=1-3.The cyclic disulfonyl imide salt is lithium salt. The non-aqueous organic solvent contains 0.001-5 mass% of cyclic polyamine compound and/or cyclic polyamide, preferably cyclic polyamine and further contains 5-40 mass% of cyclic carbonate. The cyclic polyamine is 1,4,7-triazacyclo nonane, 1,5,9-triazacyclo dodecane, 1,4,7,10-tetra azacyclo dodecane, 1,4,8,11-tetra aza cyclotetradecane or 1,4,8,11-tetramethyl-1,4,8,11-tetra aza cyclotetradecane. The cyclic polyamide compound is 1,4,7,10-tetra aza cyclotridecane-11,13-dione, 1,4,8,11-tetra aza cyclotetradecane-5,7-dione, 1,4,8,12-tetra aza cyclopentadecane-9,11-dione and cyclo(( beta )-alanyl glycyl-( beta )-alanyl glycyl). SPECIFIC COMPOUNDS - The carbonate having halogen atom is fluoroethylene carbonate, 4,4-difluoroethylene carbonate, 4,5-difluoro ethylene carbonate, 4-fluoro-4-methyl-ethylene carbonate, 4-fluoro-5-methyl-ethylene carbonate, 4-(fluoromethyl)-ethylene carbonate, 4-(trifluoromethyl)-ethylene carbonate, fluoromethyl methyl carbonate, bis(fluoromethyl)carbonate, difluoromethyl methyl carbonate, 2,2-difluoro ethylmethyl carbonate, ethyl-(2,2-difluoro ethyl)carbonate, bis(2,2-difluoroethyl)carbonate, 2,2,2-trifluoro ethylmethyl carbonate, ethyl-(2,2,2-trifluoro ethyl)carbonate and/or bis(2,2,2-trifluoro ethyl)carbonate (all claimed).