To obtain an emulsion excellent in the ratio of sensitivity to fog, pressure resistance and preservability.

This emulsion contains flat platy particles of silver iodobromide each having an aspect ratio of ≥2 by ≥50% of the total projection area of all particles. Each of the flat platy particles has at least two high silver iodide content layers separated by a low silver iodide content layer, contains ions of S, Se, Te or a mixture of them by 1×10-6-2×10-5mol per 1mol silver and has been subjected to reduction sensitization or spectral sensitization. The parallel principal planes of each of the particles are (111) faces.