To provide a heat developable material which ensures high sensitivity and low fog, improves heat resistance (the rise of fog density) and light resistance (the lowering of maximum density) after development and has superior image preservability.

In a heat developable material with a photosensitive layer containing photosensitive silver halide grains, an organic silver salt, a reducing agent and a binder and a layer adjacent to the photosensitive layer on the base, 1 a polyhalomethane compound having a phosphazene nucleus in its molecule is incorporated into at least one of the layers. 2 In the above item 1, a polyvinyl acetate derivative or a poly(meth)acrylic acid derivative is used as the binder. 3 In the above items 1 and 2, a phthalazin compound is further used. 4 In the above items, the binder is applied in the presence of a crosslinker.