A method of manufacturing a lithium-ion secondary battery of the present invention includes at least four steps as follows: an initial charging step of charging the lithium-ion secondary battery, which has not been subjected to initial charging, under a temperature environment ranging of equal to or higher than −20° C. and equal to or lower than 15° C.; an aging step of leaving the lithium-ion secondary battery under a temperature environment ranging of equal to or higher than 30° C. and equal to or lower than 80° C. after the initial charging step; a short circuit detecting step of detecting the presence or absence of a short circuit of the lithium-ion secondary battery by measuring a voltage drop quantity of the lithium-ion secondary battery and comparing the voltage drop quantity with a reference value; and a sorting step of sorting out a lithium-ion secondary battery in which no short circuit is detected.