A heating apparatus includes a tubular film, a heater, a first support member including a first regulation surface, and configured to rotatably support a first end of the film, a second support member including a second regulation surface, and configured to rotatably support a second end of the film, and a holding unit configured to hold the heater and determine a position of the heater in the longitudinal direction. Either one of the first support member and the second support member includes a positioning portion configured to determine a position of the holding unit in the longitudinal direction.