To protect a fiber-reinforced plastic member and enhance the fire resistance while retaining the mechanical strengths by laminating at least a single layer each of a low temperature foaming and fire-resistant plastic material and a high temperature foaming and fire-resistant plastic material, on at least one of the faces of the fiber-reinforced plastic member.

A thermoplastic resin is mixed with at least one additive selected from a carbonizing agent, a flame retardant and inorganic particles and a low temperature foaming agent. This mixture is molded into a platelike or a sheetlike foaming and fire-resistant plastic material L. On the other hand, the thermoplastic resin is mixed with at least one additive selected from the carbonizing agent, the flame retardant and the inorganic particles and also a high temperature foaming agent. This mixture is molded into a platelike or a sheetlike foaming and fire-resistant plastic material H. Further a foaming and fire-resistant plastic material obtained by laminating at least one layer each of the material L and the material H together, is arranged on a frame. Finally a fiber-reinforced plastic is laminated on the foaming and fire-resistant plastic material and both are integrally molded in one piece.