The present invention is to provide a nonaqueous electrolytic solution prepared by dissolving an electrolyte salt in a nonaqueous solvent, wherein the nonaqueous solvent includes 0.01 to 40% by volume of an ester having two alkyl groups at the α-position carbon of the carbonyl group and being represented by the following general formula (I), and an energy storage device. (in the above formula, R1 is an alkyl group, an alkenyl group or an alkynyl group in which at least one of the hydrogen atoms may be substituted with a halogen atom, R2 and R3 are an alkyl group in which at least one of the hydrogen atoms may be substituted with a halogen atom, and R2 and R3 may be linked to each other to form a ring. However, when R2 and R3 do not form a ring, R3 is an alkyl group in which at least one of the hydrogen atoms may be substituted with a halogen atom.).