Patent ID: 8529726

Claim:
A manufacturing method of a hollow body product, comprising: a film arrangement step in which a film is arranged on a fiber layer; a shaped member arrangement step in which a shaped member having a concave part is arranged on the film after the film arrangement step so that an opening of the concave part faces the film; a fiber layer/film gas discharging step in which gas existing between the fiber layer and the film is discharged; a film/shaped member gas discharging step in which gas existing between the film and the shaped member is discharged; a film/shaped member joining step in which the film and the shaped member are joined together after the film/shaped member gas discharging step; a fiber layer/film joining step in which the fiber layer and the film are joined together after the fiber layer/film gas discharging step; and wherein the discharging of the gas in the gas discharging steps is executed so that a condition (pressure P1 of the gas existing between the fiber layer and the film) <(pressure P2 of the gas existing between the film and the shaped member) is satisfied.