<p>In order to prevent non-sheet passing portion temperature rise occurred in a non-sheet passing area of an electromagnetic induction heating member 1, leakage of magnetic flux is reduced by setting a Curie temperature of the heating member 1 to be smaller than an acceptable upper limit temperature and setting a thickness of the heating member so that a thickness tk in a Curie temperature arrival area (P1 - P2) is larger than a thickness tn in a Curie temperature non-arrival area P2 which is a conveyance area of a material to be heated having a minimum passing size.</p>
