Abstract: A reduced-pressure heat treatment jig is used for supporting a workpiece of iron when the workpiece is subjected to heat treatment in a reduced-pressure atmosphere in which pressure is reduced compared to atmospheric pressure. The jig is formed of an iron material and is formed with a film on at least a contact surface with the workpiece, the film being formed of a material which persists during the heat treatment. The film preferably includes a metal oxide having an evaporating temperature higher than the heat treatment temperature in the reduced-pressure atmosphere. The film preferably contains aluminum oxide.