A method of producing a ceramic multilayer substrate comprising the steps of:
as a first step, producing a green composite laminate 11 containing first and second shrink-suppressing layers formed on one main surface 13 and the other main surface 14 of a green multilayer mother substrate 12 comprising a plurality of ceramic green layers 17 containing ceramic powder, the first and second shrink-suppressing layers containing a sintering-difficult powder substantially incapable of being sintered under the sintering conditions for the ceramic powder; as a second step, forming first grooves 16 extending from the first shrink-suppressing layer 13 side so as to pass through the first shrink-suppressing layer 13 and reach a part of the multilayer mother substrate 12; as a third step, firing the composite laminate 11; as a fourth step, removing the first and second shrink-suppressing layers 13 and 14 and taking out the sintered multilayer mother substrate 11; and as a fourth step, dividing the multilayer mother substrate 12 along the grooves 16, and taking out a plurality of the ceramic multilayer substrates. Thereby, the shrink in the plan direction at firing can be suppressed. Thus, a ceramic multilayer substrate having a high dimensional accuracy and a high reliability can be produced with a high production efficiency.