PURPOSE: To provide a toner for developing a negative latent image adapted to a pressure fixing method, by mixing fine particles containing an ethylenic olefin polymer and fine silica powder synthesized by the wet process further with a fine silica powder synthesized by the wet process.

CONSTITUTION: An ethylenic olefin polymer, a colorant, and fine silica powder synthesized by the wet process and containing ≥85wt% silica having 5W11pH value of 4wt% dispersion in water, preferably 7W9, and 0.01W10% sodium expressed in terms of Na2O, necessary amount of sodium to keep pH of an aq. dispersion system being 0.1W2.0%, and when needed, another binder or additive are melted and kneaded, granulated by the known process, and classified to obtain 1W35μm fine particles, and these particles are further mixed with fine silica powder synthesized with the wet process to prepare the desired developer.