Abstract: Provided is a flat fiber-reinforced plastic strand which is produced by curing a twisted resin-impregnated strand and has no disturbed fiber orientation, and a flat fiber-reinforced plastic strand sheet which is produced by using said flat fiber-reinforced plastic strands. According to a method of manufacturing the flat fiber-reinforced plastic strand 2, (a) a twisted resin-impregnated strand f2 in an uncured state, the strand including a plurality of reinforcing fibers f, is fed in a state of tension between a pair of heated steel belts 41A and 41B facing each other and making rotation movements; and (b) the resin-impregnated strand f2 is sandwiched and heated by the steel belts 41A and 41B, and pressurized from both sides of the strand f2 to form a cross section of the strand into a flat shape, and, with the shape being kept, a resin is cured and cooled.