A thermal fixing device includes: a heating member configured to be in contact with a fixation medium; a first pressing member disposed to face the heating member and applies a force directed toward both sides of the fixation medium in a direction orthogonal to a conveyance direction of the fixation medium by pressing the fixation medium to the heating member; and a second pressing member disposed to face the heating member at a position downstream in the conveyance direction with respect to the first pressing member and applies a force, which is larger than the force of the first pressing member, directed toward both sides of the fixation medium in a direction orthogonal to the conveyance direction.