A preform shaping method comprising: manufacturing a fiber stack by stacking a sheet-form fibrous component; placing on the fiber stack at least one of a subsidiary material or a component part that have flexibility; and manufacturing a preform that has a shaped configuration by pressing and pressurizing, against a mold (5; 20), the fiber stack provided with the at least one of the subsidiary material or the component part, wherein the subsidiary material is at least one of a flow medium for facilitating impregnation of the preform with a resin or a peel ply for bettering adhesion property of a surface of a composite that is molded by using the preform as a material; the component part is a copper mesh for lightning protection; the fiber stack is manufactured by stacking the sheet-form fibrous component to which a binder has been attached while being tentatively fastened by the binder by local heating; a sheet-form binder is additionally provided between the at least one of the subsidiary material or the component part and the fiber stack in order to tentatively fasten the at least one of the subsidiary material or the component part to the fiber stack; the flow medium is a mesh-form sheet configured to be provided between a surface of a dry preform and a bagging film so that fiber is sufficiently impregnated with resin even by vacuuming alone when the composite is to be formed by a vacuum-assisted resin transfer molding (VaRTM) method, the flow medium being configured to be removed from the composite after the composite is manufactured; the dry preform is a preform that is yet to be impregnated with resin; the sheet-form binder is a woven fabric material with a knitted fiber made of a thermoplastic resin or a nonwoven fabric formed from a fiber made of a thermoplastic resin; the tentative fastening and the stacking of sheet-form fibrous components are carried out automatically by using an automatic fiber stacking apparatus equipped with a heater for performing spot welding of the binder; and the tentative fastening of the at least one of the subsidiary material or the component part is carried out automatically by using a heating terminal of the heater provided on the automatic fiber stacking apparatus. manufacturing a fiber stack by stacking a sheet-form fibrous component; placing on the fiber stack at least one of a subsidiary material or a component part that have flexibility; and manufacturing a preform that has a shaped configuration by pressing and pressurizing, against a mold (5; 20), the fiber stack provided with the at least one of the subsidiary material or the component part, wherein the subsidiary material is at least one of a flow medium for facilitating impregnation of the preform with a resin or a peel ply for bettering adhesion property of a surface of a composite that is molded by using the preform as a material; the component part is a copper mesh for lightning protection; the fiber stack is manufactured by stacking the sheet-form fibrous component to which a binder has been attached while being tentatively fastened by the binder by local heating; a sheet-form binder is additionally provided between the at least one of the subsidiary material or the component part and the fiber stack in order to tentatively fasten the at least one of the subsidiary material or the component part to the fiber stack; the flow medium is a mesh-form sheet configured to be provided between a surface of a dry preform and a bagging film so that fiber is sufficiently impregnated with resin even by vacuuming alone when the composite is to be formed by a vacuum-assisted resin transfer molding (VaRTM) method, the flow medium being configured to be removed from the composite after the composite is manufactured; the dry preform is a preform that is yet to be impregnated with resin; the sheet-form binder is a woven fabric material with a knitted fiber made of a thermoplastic resin or a nonwoven fabric formed from a fiber made of a thermoplastic resin; the tentative fastening and the stacking of sheet-form fibrous components are carried out automatically by using an automatic fiber stacking apparatus equipped with a heater for performing spot welding of the binder; and the tentative fastening of the at least one of the subsidiary material or the component part is carried out automatically by using a heating terminal of the heater provided on the automatic fiber stacking apparatus.