A lithium ion secondary battery 100A has negative electrode active material particles 710A which include graphite particles that are at least partially covered by an amorphous carbon film 750. The negative electrode, active material particles 710A have a TG weight-loss-on-heating onset temperature T1 which satisfies the condition 500° C.≦T1≦615° C. and a micro-Raman G-band half-width Gh which satisfies the condition 20≦Gh≦28. This configuration makes it possible to obtain a lithium ion secondary battery 100A in which the reaction resistance in a low-temperature environment can be kept low.