A manufacturing method for a non-aqueous secondary battery includes the following steps, (a) Preparing an electrode body including a positive electrode having a positive electrode active material layer and a negative electrode having a negative electrode active material layer, (b) Constructing a battery assembly using the electrode body and a non-aqueous electrolyte, (c) Initially charging the battery assembly, (d) Aging the battery assembly at a temperature of 60 DEG C or higher, (e) Forcibly starting to discharge the battery assembly in said temperature region after lowering the temperature of the battery assembly down to a temperature region of 35 DEG C or higher and 55 DEG C or lower, (f) Adjusting the SOC of the battery assembly, (g) Measuring a voltage drop amount by self-discharging the battery assembly. And (h) determining whether or not the battery assembly is qualified based on the voltage drop amount.