Hot plate material manufacturing facility and hot plate material manufacturing method

In order to provide a hot plate material manufacturing facility and a hot plate material manufacturing method which enable endless rolling on the basis of multiple strands and with which the amount of production of a thin plate material can be increased, this hot plate material manufacturing facility is equipped with: a mill front hearth (16) arranged on the extended line of a rolling line on the entry side of a roughing mill (18), and having a length equal to or greater than the slab length corresponding to one coil; a transport hearth (15) arranged on the entry side of the mill front hearth (16), and capable of transporting a slab (W) to the mill front hearth (16); multiple slab production lines arranged on the entry side of the transport hearth (15); a joining machine (17) arranged on the exit side of the mill front hearth (16); a continuous casting machine exit-side hearth (14) arranged on the entry side of the transport hearth (15) of at least one of the slab production lines, and having a length equal t