NOVELTY - A nonaqueous electrolyte solution comprises benzene derivative (I) (greater than 0.1 %mass and 10 %mass or less) and/or benzene derivative (II) (greater than 10 %mass and 50 %mass or less). The electrolyte solution is used in secondary battery provided with positive electrode having an active material which occludes/releases a metal ion, and a negative electrode having an active material containing silicon which occludes/releases metal ion.    USE - Nonaqueous electrolyte solution is used for secondary batteries (claimed) e.g. lithium ion secondary batteries. Uses include but are not limited to notebook personal computers, mobile personal computers, electronic book players, mobile telephones, game machine devices, portable copiers and printers, liquid-crystal televisions, transceivers, electronic organizers, calculators, portable tape recorders, electric tools, hybrid vehicles, electric vehicles, large-sized fixed-type power supplies used for backup, and domestic power supplies.    ADVANTAGE - The nonaqueous electrolyte solution provides secondary batteries having suppressed gas evolution during high-temperature preservation in charge state, improved cycle characteristics and discharge characteristics, and high capacity. Reaction with negative-electrode active material is inhibited.    DETAILED DESCRIPTION - A nonaqueous electrolyte solution comprises benzene derivative of formula (I) (greater than 0.1 %mass and 10 %mass or less) and/or benzene derivative of formula (II) (greater than 10 %mass and 50 %mass or less). The electrolyte solution is used in secondary battery provided with positive electrode having an active material which occludes/releases a metal ion, and a negative electrode having an active material containing silicon which occludes/releases metal ion.    X1-X6,Y1-Y6=H, fluoro, alkyl (optionally substituted by fluoro), alkenyl, or alkynyl, with 4 or more of X1-X6 being fluoro, and 3 or less of Y1-Y6 being fluoro, and at least one of Y1-Y6 being alkyl substituted by fluoro, when it is 1 or less.