A thermal development device including: a thermal development section for
heating to develop a latent image formed on a light-sensitive surface of
a photothermographic material; a cooling section for cooling the
photothermographic material passed the thermal development section under
a condition that a cooling rate for a light-insensitive surface of the
photothermographic material is faster than the cooling rate for the
light-sensitive surface of the photothermographic material; and a
conveyance section in which the photothermographic material is conveyed
via the thermal development section and the cooling section, and the
length of the conveyance path that passes the cooling section is not more
than 1.5 times the length of the conveyance path that passes the thermal
development section.