Resin particles containing at least binding resin and wax particles having
a diameter of 30 to 600 nm are coagulated, and a resulting coagulated
product is heated. Such wax particles are manufactured, for example, by
way of a coarse particle preparing step, a slurry preparing step, a
pulverizing step, a cooling step, and a depressurizing step. Slurry of
wax coarse particles obtained by way of the coarse particle preparing
step and the slurry preparing step is directed under heat and pressure
through a pressure-resistant nozzle whereby the wax coarse particles are
pulverized into the wax particles at the pulverizing step. The cooling
step and the depressurizing step are disposed just after the pulverizing
step to prevent the wax particles from coarsening.