A fixing apparatus including a pair of rotary members forming a nip for pinching
and conveying a recording material, and a rotatable heat supplying member in contact
with at least either of the rotary members and supplying the rotary member with
heat. An image forming on the pinched and conveyed recording material is fixed
thereto by heat, and the rotary member receiving heat from the heat supplying member
has different external diameters along the longitudinal direction and the heat
supplying member has different plural external diameters so as to follow the shape
of the rotary member.