Photothermographic material

A photothermographic material containing a non-photosensitive silver salt and a photosensitive silver halide on a support, wherein the photosensitive silver halide is spectrally sensitized with a spectral sensitizing dye represented by the following formula (I) so that maximum spectral sensitivity wavelength is capable of becoming longer than 730 nm and the conditions defined by the following formulas (1) and (2) and/or the conditions defined by the following formulas (3) and (4) is capable of being satisfied:

• 300≧S(λ max)/S(λ max+30 nm)≧4.5 Formula (1)
• 30≧S(λ max)/S(λ max−30 nm)≧2 Formula (2)
• 300≧Abs.(λ max)/Abs.(λ max+30 nm)≧4.5 Formula (3)
• 30≧Abs.(λ max)/Abs.(λ max−30 nm)≧2 Formula (4)
• wherein, in the above formulas, λmax denotes maximum spectral sensitivity wavelength, S(λmax) denotes spectral sensitivity at a wavelength of λmax and Abs. (λmax) denotes optical density at a wavelength of λmax,
• wherein Z1 and Z2 may be the same or different from each other, and they represent sulfur atom or selenium atom;
• Y1 and Y4 represent hydrogen atom, and Y1, when Y2 is not hydrogen atom and Y4, when Y5 is not hydrogen atom, also represent methyl group, ethyl group, hydroxy group or methoxy group;
• Y2 and Y5 represent hydrogen atom, an alkyl group having 3 or less carbon atoms, which may be substituted, hydroxy group, methoxy group, ethoxy group, a monocyclic aryl group, acetylamino group or propionylamino group;
• Y2 and Y1 or Y5 and Y4 may be bonded together to form methylenedioxy group, trimethylene group or tetramethylene group;
• Y3 and Y6 represent hydrogen atom, or Y3 and Y2 or Y6 and Y5 may be bonded together to form methylenedioxy group, ethylenedioxy group, trimethylene group, tetramethylene group or tetradehydrotetramethylene group;
• R1 and R2 may be the same or different from each other, and they represent an alkyl group or alkenyl group having 10 or less carbon atoms in total, which may be substituted;
• R3 and R5 represent hydrogen atom, or R3 and R1 or R5 and R2 may be bonded together to form a 5- or 6-membered ring;
• R4 represents hydrogen atom or a lower alkyl group which may be substituted;
• R6 represents hydrogen atom, methyl group, ethyl group or propyl group;
• R7 represents a lower alkyl group which may be substituted, or phenyl group which may be substituted;
• X represents a counter ion required for neutralizing the electric charge;
• n represents 0 or 1;
• and when the compound forms an intramolecular salt, n is 0.