PURPOSE: To obtain a damping composite steel panel good in heat resistance, oil resistance and degreasing resistance and having sufficient bonding strength after processing and sufficiently usable even under high temp. environment by alternately arranging a thermoplastic resin and a thermosetting resin between steel panels in a stripe state.

CONSTITUTION: A damping composite steel panel has such a structure that a damping resin is held between two steel panels, that is, a thermosetting resin and a thermoplastic resin are alternately arranged between two steel panels in a stripe state. At the time of the coating with the resins in the damping composite steel panel, a steel strip 4 is moved in the direction shown by an arrow by rotating a backup roll 5. When the moving steel strip 4 is passed under the liquid dam 8 alternately holding the thermosetting and thermoplastic resins 2, 3 within a plurality of the side dams 7 being in contact with a comma roll 6, the thermosetting and thermoplastic resin 2, 3 are arranged on the steel strip 4 and sent out by the comma roll 6 while held to a predetermined resin thickness. Thereafter, a steel strip is bonded to the thermosetting and thermoplastic resins 2, 3 to obtain the composite damping steel panel.