FIXING APPARATUS

A fixing apparatus having a first rotation member, an elongated heater having a heat generating member and a substrate on which the heat generating member is provided and being disposed in an internal space of the first rotation member, a heater holder that holds the heater, a stay that supports the heater holder, a sliding sheet being disposed between the heater and the first rotation member and sliding on an inner circumferential surface of the first rotation member, and a second rotation member forming a nip portion with the heater through the first rotation member, and, in the nip portion, a toner image formed on a recording material being heated and fixed, in which, when a longitudinal direction of a surface of the substrate on which the heat generating member is provided, a transverse direction that is orthogonal to the longitudinal direction.