A secondary battery includes: a cathode including an active material; an anode; and an electrolytic solution, and the active material includes a plurality of active material particles as primary particles and a carbon material. The active material particles contain a polyanion-based compound. The carbon material contains a first carbon material present on surfaces of the active material particles, and a second carbon material present between the active material particles provided with the first carbon material. A ratio B/A between a total carbon amount A and a surface carbon amount B of the active material satisfies 7