PURPOSE: To further reduce fog and the rate of scattering between lines while maintaining sufficiently high density, to faithfully develop an electrostatic latent image and to enhance the sharpness of letters or lines.

CONSTITUTION: A carrier 36 and a toner 40 are blended with an electric field regulating agent 38 to which an electric charge controlling agent having the same polarity as the toner and an additive (hydrophobic silica) having the same polarity as the toner have been added to obtain the objective electrostatic latent image developer. By the presence of the electric field regulating agent, the fogging of an image nonprinted part is effectively suppressed, the toner can be faithfully stuck to an electrostatic latent image on a photoreceptor 1 and the sharpness of letters or lines can be effectively enhanced. Since the electric field regulating agent and the additive added to the surfaces of the particles of the agent are highly charged to the same polarity as the toner, the quantity of electric charges on the toner is regulated to the standard value and fog and the rate of scattering between lines can further be reduced while especially maintaining sufficiently high density.