In a stretching zone (Z2) included in a plurality of zones for performing temperature control for heating or cooling of a film, the plurality of zones being arranged in the conveyance direction of the film, the film is stretched in a direction tilted in relation to the width direction of the film. The film is heated by a heating unit (11) having a heating region (H) positioned facing the conveyed film and positioned along a direction intersecting at an intersection angle φ with the conveyance direction in the plane of the film, in at least one zone including the stretching zone (Z2) and positioned further downstream in the conveyance direction form the stretching zone (Z2). At this time the intersection angle φ of the heating region (H) is adjusted in accordance with the orientation direction of the film stretched in the stretching zone (Z2).