PURPOSE: To obtain a large current multilayer printed board by forming the periphery of a conductor layer of an inner layer of the multilayer printed board in which a copper foil and an insulting layer area associated of a material having satisfactory thermal conductivity.

CONSTITUTION: Copper foils C1, C2 in an inner layer are laminated on the same insulating layer as copper foils a2, a3, and insulated from the foils a2, a3. The foils C1, C2 are disposed on a part corresponding to the copper foil pattern of an outer layer of the inner layer through insulating layers b1, b2 from the circuit pattern of copper foils a1, a4 of an outer layer. When a large current circuit pattern is formed on the foils a1, a4 and a small current circuit pattern is formed on the foils a2, a3, heat generated from the foils a1, a4 due to a large current can be released to the foils C1, C2 through the layer b1, b3, thereby suppressing the temperature rise of the foils a1, a4 to a low value.