PURPOSE: To fibrillate sufficiently a reinforced fiber bundle, impregnate a matrix material in the most uniformized state and provide superior physical properties by attaching a fibrillating section for bringing the reinforced fiber bundle into contact with fluorine resin prior to the process of impregnating the reinforced fiber bundle with the matrix material.

CONSTITUTION: A fibrillating section 5 constituted of a plurality of rollers 3 and 4 for fibrillating fiber while a reinforced fiber bundle 6 is provided between a bundling agent cleaning tank 1 and an aluminum hot melt tank 2 of a composite material manufacturing device 10 for manufacturing, for example, fiber reinforced metal(FRM). Respective rollers 3 and 4 are constituted by mounting shrinkable Teflon tubes of fluorine resin on respective metal rollers. The reinforced fiber bundle 6 is brought into contact with fluorine resin in the process prior to impregnating the reinforced fiber bundle 6 with a matrix material. The reinforced fiber bundle 6 is fibrillated sufficiently by the arrangement, and the matrix material is applied for impregnation in the uniformized state. Thus a composite material of superior physical properties can be manufactured.