The manufacturing method of the invention includes the steps of: providing a positive electrode and a negative electrode (S10), a sodium ingredient being included in either the positive electrode or the negative electrode; producing an electrode assembly from the provided positive electrode and negative electrode (S20); producing a battery assembly in which the electrode assembly is housed in a battery case (S30); injecting a nonaqueous electrolyte solution into the battery case (S40), the nonaqueous electrolyte solution including at least lithium bis(oxalato)borate, a fluorophosphate compound, a carbonate solvent and an ether solvent, and the amount of ether solvent included in the nonaqueous electrolyte solution being less than 10 vol % when the amount of nonaqueous solvent included in the nonaqueous electrolyte solution is set to 100 vol %; and charging and discharging the battery assembly (S50).