A nonaqueous electrolytic solution having an electrolyte salt dissolved in a nonaqueous solvent, containing a compound of formula (X): where R10 and R20 are each a group selected from an alkyl having 1 to 8 carbon atoms, an alkenyl having 2 to 6 carbon atoms, an alkynyl having 3 to 6 carbon atoms, and an aryl having 6 to 12 carbon atoms, or a lithium; and X is a polar group (i) containing a —C(═O), a —P(═O), or an —S(═O)2 group, a polar group (ii) containing a —CN or an alkyl group having 1 to 6 carbon atoms, in which a part of hydrogen atoms is substituted with a fluorine atom, or a 4- to 7-membered ring polar group (iii) containing a —C(═O)—O— or a —C(═O)—N— group, where when X is a 4- to 7-membered ring polar group (iii) containing —C(═O)—N—, at least one of R10 and R20 is lithium.