Black and white photothermographic material and image forming method

An image forming method comprising:

• (a) providing a black and white photothermographic material comprising, on at least one side of a support, an image forming layer comprising at least a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions, and a binder, wherein
• 1) the non-photosensitive organic silver salt comprises at least one compound selected from the group consisting of a silver salt of an azole compound and a silver salt of a mercapto compound,
• 2) the photosensitive silver halide has a spectral sensitizing dye in the form of a multilayer adsorbed on its surface, and
• 3) 50% by weight or more of the binder is formed by a hydrophilic binder;
• and
• (b) subjecting the black and white photothermographic material to imagewise exposure and thermal development,
• wherein the imagewise exposure comprises bringing the black and white photothermographic material into close contact with a fluorescent intensifying screen containing a fluorescent substance, wherein 50% or more of emission light of the fluorescent substance has a wavelength of 350 nm to 420 nm, and applying imagewise X-ray exposure.