A toner is composed of toner particles which contain at least a binder resin, a colorant, and a release agent. As to particle size distribution and particle number distribution of the toner particles, a volume average particle size of the toner particles is set to be 3.0 μm to 6.0 μm, and a content of 5.0 μm or smaller toner particles is set to be 40% by number while a content of 8.0 μm or larger toner particles is set to be less than 2% by volume. Furthermore, an amount of the release agent in toner particle surface is set to be 0.7% by weight or more and 1.8% by weight or less. And furthermore, the release agent is a petroleum-based release agent.