Patent ID: 7166408

Claim:
An image forming method comprising: providing a photothermographic material having image forming layers containing at least a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent, and a binder on both surfaces of a support, imagewise exposing the photothermographic material with a fluorescent intensifying screen, and thermally developing the photothermographic material in a thermal developing apparatus having a heating section, wherein: the heating section has at least two heating means in which a first heating means for heating a first surface of the photothermographic material and a second heating means for heating a second surface of the photothermographic material are disposed separately in a back to back relation with each other along a conveying route of the photothermographic material, which is sandwiched by the first and second heating means, so that the first surface is heated first and thereafter the second surface is heated; and a difference between a sensitivity when the photothermographic material is developed at 25° C. and relative humidity of 75% and a sensitivity when the photothermographic material is developed at 25° C. and relative humidity of 20% is 0.20 or less.