To provide a method capable of determining the heating sequence rationally and generally.

The sectional quadratic moment of a metal plate at each position of heating filaments are calculated to a plurality of heating filaments fixed on a metal plate based on the calculated heating plan in advance (Step S1). The heating filament, of which calculated sectional quadratic moment being the maximum, is selected and set as the first of the heating sequence (Step S2). The shape of the metal plate, which deforms due to the heating of the selected heating filament, is estimated using elastic FEM analysis (Step S3). After the calculation of the sectional quadratic moment of the metal plate at each positions to the heating filament that remains on the estimated metal plate (Step S4), returning to Step S2, the filament, whose sectional quadratic moment being the largest, is selected as the heating filament to be subsequently heated. Thereafter the steps are repeated to select the heating sequence for all heating filaments.