PURPOSE: To enhance sensitivity and an interimage effect by using an emulsion comprising specified flat silver halide grains.

CONSTITUTION: One silver halide emulsion layer contains the flat silver halide grains having a thickness of <0.5mμ, a diameter of ≥0.3mμ, and a diameter to thickness ratio of ≥2. A part of ≥50 number % of the flat grains has each ≥10 dislocation lines and the relative standard deviation of silver iodide content in each of the flat grains is ≤30%. The photosensitive material contains in one layer the compound represented by formula I in which A is an oxidation- reduction mucleus or its precursor, and it is an atomic group to be oxidized during development, resulting in releasing (Time)t-X from A-(L)m-(G)n; Time is a timing group releasing X after being released; X is a development inhibitor residue; L is a divalent bonding group; G is a polar group; and each of n, m, and t is 0 or 1.