PURPOSE: To obtain a three-layered clad plate having good adhesiveness and corrosion resistance by inserting, by casting, the metallic plate joined via a release agent into the 2nd metal, blooming the plate and separating the plates from the joined part, hot-rolling the separated plate, further inserting, by casting, the separated plate into the 3rd metal and rolling the plate.

CONSTITUTION: Two sheets of the 1st metallic plates 1 consisting of Ni, etc. are joined to each over via a release agent 5 and are suspended in a casting mold 3. The 2nd metal 2 such as stainless steel or the like is cast into the mold to insert the 1st plates 1 by casting into said metal. The cast ingot consisting of two kinds of such metallic layers are subjected to soaking and blooming and are separated to two parts from the agent 5 part. The two billets are hot-rolled to form clad metallic plates. After the surfaces of two sheets of the clad plates 7 are cleaned, the plates are symmetrically suspended in the mold 3 and the 3rd metal such as molten cast steel or the like is cast between the two plates 7 to obtain the cast ingot consisting of at least three kinds of the metallic layers. Such cast ingot is subjected to soaking, blooming and cutting by which the clad plate having a desired size is obtd.