The invention provides a photothermographic material including, on a same
surface of a substrate, photosensitive silver halide grains, a
non-photosensitive organic silver salt, a reducing agent and a binder, in
which the photosensitive silver halide grains include iridium and a metal
of groups 3 to 10 of the periodic table other than iridium, and 90% or
more of the total iridium amount within the grain are contained in a core
of 50% or less of the grain.