A first process in which a fiber reinforced base is placed in a cavity of a molding die and then resin is injected into the cavity of the molding die in a state where the molding die is opened by a sum of a distance X1 and a distance at the time of completion of molding; a second process in which the molding die is closed to a state where the molding die is opened by a sum of a distance X2 and the distance at the time of completion of molding while resin in the cavity is being drained; and a third process in which the drain of the resin from the cavity is stopped and then the molding die is closed to the distance at the time of completion of molding while a die clamping pressure is maintained at a predetermined value to cure the resin, are carried out sequentially.