PURPOSE: To obtain a uniform mat consisting of perfectly dispersed strands by feeding a glass fiber roving drawn from a winding into a narrow passage and by spouting pressurized gas into the passage when the roving is cut.

CONSTITUTION: Glass fibers are bundled with a binder to form a strand, and a plurality of strands are wound as a roving. When this roving is drawn from the winding and cut to produce a mat, the roving is fed into narrow passage 1. Pressurized gs of above 1kg/cm2G is spouted from introduction hole 3 through small tip 4 opening on passage 1 and exhausted from outlet 5. The roving fed is dispersed into strands with the impact force of the gas, and the strands do not adhere. The cross-sectional area and length of passage 1, the vol. of the gas spouted, roving speed, etc. are decided separately. The resulting mat is suitable for FRP reinforcement.