Method for producing upsized FRP member

A method for manufacturing a large FRP member comprising the following steps (A) to (F),

• the step (A) being a step of disposing a preform containing at least one reinforcing fiber base material on a surface of a molding die;
• the step (B) being a step of covering a molding portion with a bagging material or a mold and providing at least one suction port and at least one resin injection port for sealing;
• the step (C) being a step of evacuating the molding portion through the suction port;
• the step (D) being a step of heating the molding portion by placing the molding die in a sealed chamber which is heat insulated with a heat insulating material, and the entire molding portion is heated by supplying hot air;
• the step (E) being a step of injecting a thermosetting resin from the resin injection port for impregnating the reinforcing fiber base material with the resin while a temperature Tm of the molding die and a temperature Tv of the bagging material or the mold are both set to room temperature or more, and a difference ΔT in temperature therebetween is set to 10° C. or less;
• the step (F) being a step of curing the resin by maintaining the molding portion at a predetermined temperature Tpc which is equal to or more than room temperature.