A method of forming an image comprising the steps of: (a) irradiating an silver salt photothermographic material with a laser beam emitted by a scanning exposing device in a laser imager, provided that the scanning exposing device comprises a laser diode, a polygon mirror, and an imaging lens made of a resin; and (b) developing the irradiated silver salt photothermographic material to obtain an image by applying heat, wherein the silver salt photothermographic material comprises a first radiation absorbing compound on a side of the support which is provided with the photosensitive layer, provided that a total absorbance of the first radiation absorbing compound is from 0.3 to 1.00 at an irradiation wavelength; and a second radiation absorbing compound on a side of the support opposite the photosensitive layer, provided that a total absorbance of the second radiation absorbing compound is from 0.20 to 1.50 at an irradiation wavelength.