A silver halide emulsion at least containing a dispersion medium and silver halide grains, in which the grains of 20% or more of the total projected areas of all the silver halide grains are substantially octahedral grains as derived from cubic grains by deleting substantially two diagonal apexes of the eight apices of the cubic grain, the outer surface of the deleted site is a {111} plane, and the main plane (the maximum flat plane of the outer surface of the grain) is a {100} plane. Since the sites of forming chemically-sensitized nuclei are defined in the emulsion grains, dispersion of latent images formed is inhibited. The emulsion has a high sensitivity and has excellent reciprocity law failure characteristics, developability and formed image quality.