A photothermographic material contains a compound of formula (I): ##STR1## wherein X represents --N.dbd., --N(R)--, --O--or --S--wherein R represents hydrogen, hydroxy, aliphatic hydrocarbon, aryl or heterocyclic group, Z represents a valence bond or a group of non-metallic atoms necessary to form a 5 to 7-membered ring with X, and each of Q.sub.1 and Q.sub.2 represents a group of non-metallic atoms necessary to form an aromatic hydrocarbon ring or aromatic heterocycle fused to the ring completed by Z. The material has high sensitivity in the infrared region and a minimal sensitivity change with varying storage conditions.