PURPOSE: To improve shearing strength by making the title plastics possess strength in the direction meeting at right angles with fiber along with possession of sufficient strength in a pull-off direction, by a method wherein a part of prepreg to be sent out of an unwinding stand is cut off and made to mix with uncut-off prepreg, in a pull-off processing of FRP.

CONSTITUTION: A cutting device 6 cutting off prepreg into a predetermined length is provided between each of prepreg delivery devices 5 of an unwind stand 1 of a glass roving. The prepreg is introduced into the cutting device 6 at an identical rate with a pull-off rate. As the prepreg cut off here is entered between long-fiber prepreg and entangled each other, a drawn material which is strong in the right angle direction of the fiber can be manufactured.