A method of forming a rolled food dough (PP) from a food dough piece (P) comprising steps of: conveying a food dough piece (P) into a space between a middle-speed conveyor and a high-speed conveyor , a speed of the high-speed conveyor being higher than a speed of the middle-speed conveyor , the high-speed conveyor facing the middle-speed conveyor and moving in the same direction as the middle-speed conveyor ; feeding a high-speed-conveyor-side portion of the food dough piece (P) faster than a middle-speed-conveyor-side portion of the food dough piece (P) due to a speed difference between the middle-speed conveyor and the high-speed conveyor , so as to deflect a downstream end portion (PL) of the food dough piece (P) toward a middle-speed-conveyor side; causing the deflected downstream end portion (PL) of the food dough piece (P) to collide with an upstream end portion of a low-speed conveyor which is disposed downstream of the middle-speed conveyor , a speed of which is lower than the middle-speed conveyor , and which moves in the same direction as the middle-speed conveyor ; forming a buckling part (PS) in the deflected downstream end portion (PL) of the food dough (P) due to a speed difference between the middle-speed conveyor and the low-speed conveyor , and folding the deflected downstream end portion (PL) at the buckling part (PS); adhesively pressing the folded downstream end portion (PL) of the food dough piece (P) between the low-speed conveyor and the high-speed conveyor facing the low-speed conveyor so as to form a rolling core (PA); and rolling the food dough piece (P) around the rolling core (PA) between the low-speed conveyor and the high-speed conveyor due to a speed difference between the low-speed conveyor and the high-speed conveyor so as to form a rolled food dough (PP). conveying a food dough piece (P) into a space between a middle-speed conveyor and a high-speed conveyor , a speed of the high-speed conveyor being higher than a speed of the middle-speed conveyor , the high-speed conveyor facing the middle-speed conveyor and moving in the same direction as the middle-speed conveyor ; feeding a high-speed-conveyor-side portion of the food dough piece (P) faster than a middle-speed-conveyor-side portion of the food dough piece (P) due to a speed difference between the middle-speed conveyor and the high-speed conveyor , so as to deflect a downstream end portion (PL) of the food dough piece (P) toward a middle-speed-conveyor side; causing the deflected downstream end portion (PL) of the food dough piece (P) to collide with an upstream end portion of a low-speed conveyor which is disposed downstream of the middle-speed conveyor , a speed of which is lower than the middle-speed conveyor , and which moves in the same direction as the middle-speed conveyor ; forming a buckling part (PS) in the deflected downstream end portion (PL) of the food dough (P) due to a speed difference between the middle-speed conveyor and the low-speed conveyor , and folding the deflected downstream end portion (PL) at the buckling part (PS); adhesively pressing the folded downstream end portion (PL) of the food dough piece (P) between the low-speed conveyor and the high-speed conveyor facing the low-speed conveyor so as to form a rolling core (PA); and rolling the food dough piece (P) around the rolling core (PA) between the low-speed conveyor and the high-speed conveyor due to a speed difference between the low-speed conveyor and the high-speed conveyor so as to form a rolled food dough (PP). <EOS>