PURPOSE: To obtain a heating installation for direct rolling capable of using hearth rolls for the whole transportation of stocks and reducing the flaws of hearth and stock, by dividing a heating furnace in two by arranging a heat retaining furnace on a direct stock-transporting line set between a continuous casting installation and a rolling installation and arranging a heating furnace at the side of rolling installation.

CONSTITUTION: A billet delivered from a continuous casting installation (a) is fed from a roll table (b) to a billet charging bed (d). The billet discharged from the bed (d) is fed to a heating furnace (i) from a carry-in table (e) of heat retaining furnace, and is heated up to a rolling temperature. Next, the billet heated in the furnace (i) is fed to a rolling installation (l) through a roll table (i) at the rear side of furnace (i). Further, a heat retaining furnace (q) installed adjacently to a roll table (f), is heated by the waste heat of a combustion gas of furnace (i), and the heat of spare stocks is insulated to absorb the imbalance between the production rates of continuous casting and rolling. In said process, the hearth rolls can be used for the whole transportation of stock.