A fixing apparatus that transports a recording medium carrying a developer image on it and heats the developer image to fix into the recording medium, the apparatus comprising: a rotating body (1, 1a, 1b) that extends in a first direction parallel to a rotational axis of said rotating body and generates heat; an endless belt that runs in a second direction perpendicular to the first direction; a belt guide (3A, 3C, 3D) on which said endless belt is loosely entrained; and a pressurizing mechanism (7, 6, 20, 50) that engages said endless belt from inside and urges said endless belt against said rotating body (1, 1 a, 1 b), wherein the pressurizing mechanism includes a pressure roller that extends parallel to said rotating body (1, 1a, 1b) and urges said endless belt against said rotating body (1, 1a, 1b) while rotating, and a pressure pad that extends parallel to said rotating body, the pressure pad including a pressure surface that urges said endless belt against said rotating body, wherein said rotating body (1, 1 a, 1 b) is further adapted to rotate and drive said endless belt in rotation in such a way that the recording medium is pulled in between said rotating body (1, 1 a, 1 b) and said endless belt, characterized in that the pressure surface extends more outwardly nearer a longitudinal middle of the pressure surface than at longitudinal ends (62ae1, 62ae2) of the pressure surface, and the pressure roller has a large diameter at its longitudinal middle and a small diameter at its longitudinal ends (71ae1, 71ae2) such that the diameter of the pressure roller is larger nearer the longitudinal middle (71 ac) of the pressure roller than at the longitudinal ends (71ae1, 71ae2). a rotating body (1, 1a, 1b) that extends in a first direction parallel to a rotational axis of said rotating body and generates heat; an endless belt that runs in a second direction perpendicular to the first direction; a belt guide (3A, 3C, 3D) on which said endless belt is loosely entrained; and a pressurizing mechanism (7, 6, 20, 50) that engages said endless belt from inside and urges said endless belt against said rotating body (1, 1 a, 1 b), wherein the pressurizing mechanism includes a pressure roller that extends parallel to said rotating body (1, 1a, 1b) and urges said endless belt against said rotating body (1, 1a, 1b) while rotating, and a pressure pad that extends parallel to said rotating body, the pressure pad including a pressure surface that urges said endless belt against said rotating body, wherein said rotating body (1, 1 a, 1 b) is further adapted to rotate and drive said endless belt in rotation in such a way that the recording medium is pulled in between said rotating body (1, 1 a, 1 b) and said endless belt, characterized in that the pressure surface extends more outwardly nearer a longitudinal middle of the pressure surface than at longitudinal ends (62ae1, 62ae2) of the pressure surface, and the pressure roller has a large diameter at its longitudinal middle and a small diameter at its longitudinal ends (71ae1, 71ae2) such that the diameter of the pressure roller is larger nearer the longitudinal middle (71 ac) of the pressure roller than at the longitudinal ends (71ae1, 71ae2).