Abstract: To produce a green composite laminate 11, a green multilayer collective substrate 13 containing low-temperature sinterable glass ceramic powder as a main ingredient is disposed between first and second shrinkage-restraining layers 14a and 14b containing alumina powder as a main ingredient. Grooves 16 are formed on one main surface 11a of the green composite laminate 11 such as to pass through the first shrinkage-restraining layer 14a and the green multilayer collective substrate 13 and reach the second shrinkage-restraining layer 14b, but not to reach the other main surface 11b of the green composite laminate 11. The green composite laminate 11 provided with the grooves 16 is sintered under conditions where the low-temperature sinterable glass ceramic powder is sintered and the green first and second shrinkage-restraining layers 14a and 14b are removed to prepare a plurality of ceramic multilayer substrates.