To obtain {100} flat plate-like silver halide particles high in silver concentration in an emulsion at the time of completing a particle growth process and large in average particle diameter and high in average aspect ratio by growing the high chloride {100} flat plate-like particles from a particle nucleus host, and at that time allowing a secondary particle group to act as a silver halide source for growing the flat plate-like particles.

The silver halide emulsion containing a gelatin deflocculant and a specified aqueous dispersion medium and silver halide particle nuclei containing 1-10% of the total silver amount in the photographic emulsion and bromide for promoting growth of {100} flat plate-like particles is prepared in a reaction vessel. The secondary silver halide particle group is formed by adding halide ions containing chloride in an amount of ≥50 mol.% of silver the emulsion while limiting the total volume to 0.7-2.0 l/mol of silver and finishing addition of the silver for forming the emulsion layer. The flat plate-like particles having the {100} principal faces are grown by raising the temperature of the dispersion medium and ripening the secondary particle group.