Provided is a method for manufacturing a fiber reinforced resin molded article capable of detecting a resin impregnation state in a fiber layer of a preform at a position corresponding to a resin flow end portion and uniformly impregnating the fiber layer of the preform with resin, and such a manufacturing device thereof. For example, when a relation between a resin pouring time and a pressure of resin detected by a pressure sensor satisfies a predetermined condition or when the pressure of resin detected by the pressure sensor is higher than or equal to a predetermined value, it is determined that the resin flow end portion of the preform is completely impregnated with resin.