A method for manufacturing a thin plate, the method comprising: placing (S100) a copper piece on a side of an aluminum piece ; forming (S200) a heterogeneous metal joined body by performing friction welding on the side of the aluminum piece and a side of the copper piece to thereby form a spread layer of the aluminum piece on the side of the aluminum piece , and a spread layer of the copper piece on the side of the copper piece , the respective spread layers of the aluminum piece and the copper piece being mixed into a mixed layer that is then cured, and characterised in that : the width of the heterogeneous metal joined body is from 1mm to 10mm; and further characterised by the following: removing beads building up during friction welding using a bead remover; inserting the heterogeneous metal joined body into a rolling mill or equipment and forming (S300) the thin plate having a thickness from 50 μ m to 50,000 μ m by roll-milling the heterogeneous metal joined body in said rolling mill or equipment in a widthwise direction thereof, and wherein the rolling mill or equipment includes a plurality of rolls , which are performing roll-milling on the heterogeneous metal joined body in the widthwise direction, a plurality of adjusting guides installed on both sides of the rolls and tight-contactingly which are moving to the rolls to thereby adjusting the width of the heterogeneous metal joined body, and a plurality of guide controllers which are controlling the adjusting guides to tight-contactingly move from both sides of the rolls to the rolls, corresponding to a preset width of the heterogeneous metal joined body. placing (S100) a copper piece on a side of an aluminum piece ; forming (S200) a heterogeneous metal joined body by performing friction welding on the side of the aluminum piece and a side of the copper piece to thereby form a spread layer of the aluminum piece on the side of the aluminum piece , and a spread layer of the copper piece on the side of the copper piece , the respective spread layers of the aluminum piece and the copper piece being mixed into a mixed layer that is then cured, and characterised in that : the width of the heterogeneous metal joined body is from 1mm to 10mm; and further characterised by the following: removing beads building up during friction welding using a bead remover; inserting the heterogeneous metal joined body into a rolling mill or equipment and forming (S300) the thin plate having a thickness from 50 μ m to 50,000 μ m by roll-milling the heterogeneous metal joined body in said rolling mill or equipment in a widthwise direction thereof, and wherein the rolling mill or equipment includes a plurality of rolls , which are performing roll-milling on the heterogeneous metal joined body in the widthwise direction, a plurality of adjusting guides installed on both sides of the rolls and tight-contactingly which are moving to the rolls to thereby adjusting the width of the heterogeneous metal joined body, and a plurality of guide controllers which are controlling the adjusting guides to tight-contactingly move from both sides of the rolls to the rolls, corresponding to a preset width of the heterogeneous metal joined body. <EOS>