PURPOSE: To reduce the burring part caused on a clad plate by rolling the peripheral edge part of the non-cladding face of a base metal and cladding material by working it in taper shape in advance, in case of manufacturing a clad plate by rolling the composite slab composed of the base metal and cladding material.

CONSTITUTION: A taper part 11C is formed by a gas cut on the non-cladding face 11 of a base metal 1 and cladding material 2, a taper part 110 is formed by pressing by a press metal die 13 and support board 12 at the cladding face side or a taper part 11E is formed by pressing with rolling by pressure rolls 14, 15 the upper and lower faces 11B which become the non-cladding face that two sheets of base metals or cladding metals 11 are overlapped, in case of manufacturing a clad plate by hot-rolling with work rolls 5, 6 the composite slab 4 formed by the base metal 1 and cladding material 2. The base metal and cladding material are hot-rolled by overlapping them with the face having these taper parts as the non-cladding face and the burring part is extremely reduced and the clad plate can be manufactured in high yield.