Abstract: A molding die is mainly constituted of a die surface shell layer (15) having a die surface (32) responsive to the shape of a composite item and a support (16) supporting the die surface shell layer (15). The die surface shell layer (15) is made of a material having air permeability, and a prepreg material (34) is placed on a die-shaped surface (32) thereof. Then, the prepreg material (34) is covered with a nonpermeable vacuum bag film (35), and a cavity portion (30) of the support (16) is evacuated. The die surface shell layer (15) has air permeability, whereby it follows that air present on the die-shaped surface (32) is also discharged into the cavity portion (30) through the die surface shell layer (15). Consequently, the prepreg material (34) is pressed against the die-shaped surface (32) by the atmospheric pressure outside the vacuum bag film (35), and strongly adheres.

Abstract: A molding die is mainly constituted of a die surface shell layer (15) having a die surface (32) responsive to the shape of a composite item and a support (16) supporting the die surface shell layer (15). The die surface shell layer (15) is made of a material having air permeability, and a prepreg material (34) is placed on a die-shaped surface (32) thereof. Then, the prepreg material (34) is covered with a nonpermeable vacuum bag film (35), and a cavity portion (30) of the support (16) is evacuated. The die surface shell layer (15) has air permeability, whereby it follows that air present on the die-shaped surface (32) is also discharged into the cavity portion (30) through the die surface shell layer (15). Consequently, the prepreg material (34) is pressed against the die-shaped surface (32) by the atmospheric pressure outside the vacuum bag film (35), and strongly adheres.