A toner to develop electrostatic latent images which uses an appropriate combination of a high molecular weight binder resin and a low molecular weight binder resin, an appropriate amount of a releasing agent, and a combination of silica particles and iron oxide particles as external additives, and thus has the following effects: the toner may reduce a generation amount of ultra-fine particles (UFPs) and have enhanced fluidity, charging uniformity, charging stability, transfer efficiency, fixability, durability and a cleaning ability.