An induction heating roller apparatus comprises:a stationary shaft 23 having a plurality of hydraulic operating mechanisms 27 arranging in one line in the direction of axis, each hydraulic operating mechanism being made up of a cylinder 25 and a piston 26, and magnetic flux generating mechanisms 32 and 35 which comprise iron cores 30 and 33 and induction coils 31 and 34 wound on the latter 30 and 33; anda roller 21 which is rotatably supported on the stationary shaft 23, and has a cylindrical wall which includes jacket chambers 22 filled with a two-phase (gas and liquid) heating medium. In the apparatus, the magnetic flux generating mechanisms 32 and 35 being arranged on both sides of the stationary shaft in the direction of axis in such a manner that they are circumferentially 90.degree. away from the hydraulic operating mechanisms arranged in one line. Therefore, it is possible to provide an induction heating roller apparatus which is able to more accurately amend the configuration of the roller according to the amount of deflection, to make the surface temperature of the roller more uniform, and to perform thermal conversion with high efficiency.