PURPOSE: To contrive the improvement of yield and the simplification of the manufacturing process, by coiling a specified initial coiling length of the hot strip together with a heat insulating material prepared in a papery form, into the down-coiler of the hot strip mill.

CONSTITUTION: The high temperature rolled material 2 running out of the hot strip mill is conveyed by the hot-run table 1 ane is coiled by the down-coiler 3. A papery formed heat insulating material 4 is sent out at a speed synchronized to that of the hot strip 2,whose specified initial coiling length is hereby coiled together with the heat insulating material 4. As a result, over the specified initially coiled length where the heat insulating material 4 is coiled together with the hot strip 2, the hot strip 2 and the heat insulating material 4 make layers overlapping alternately in the coil. Hereby, the heat transmission from the hot strip 2 to the reel 6 is hindered, and the radical temperature drop of the hot strip 2 is prevented, so that either the improvement of yield or the omission or reheating process becomes possible.