A positive electrode active material contains at least: fluorine in an amount not lower than 0.08 mass %; carbon in an amount not lower than 0.02 mass %; and lithium-metal composite oxide particles making up the remainder. The lithium-metal composite oxide particles contain nickel in an amount not lower than 60 mol % of the total amount of metallic elements. At least a partial amount of each of the fluorine and the carbon is present on surfaces of the lithium-metal composite oxide particles.