PURPOSE: To provide a manufacturing method of low temperature baking multilayer ceramic board packaging LSI, chip part, etc., using Cu as the conductor material for mutual wiring of the elements.

CONSTITUTION: This manufacturing method is composed of five steps enumerated as follows, i.e., a first step of manufacturing green sheets 11 of ceramic material mixed with an organic binder and a plasticizer, a second step of printing a specific circuit pattern in pastes 12, 13 mainly comprising the cuprous oxide on the green sheets 11, a third step of forming green sheet laminated bodies by laminating the green sheets 11 printed with the circuit pattern, a fourth step of removing the binder by decomposing and scattering the organic binder in the green sheet laminated bodies as well as a fifth step of reducing and baking step of reducing said cuprous oxide simultaneously baking the ceramic in the reducing atmosphere in oxygen concentration not exceeding 4% after finishing the binder removing step.