Provided is a method for manufacturing ceramic multilayer substrates, by which ceramic multilayer substrates can be accurately and easily manufactured. An assembled substrate of the ceramic multilayer substrates is also provided. An unfired ceramic laminate (12a), which has an unfired conductor pattern (14) and includes portions to be a plurality of ceramic multilayer substrates (10a, 10b, 10c) between the layers of a plurality of unfired ceramic green sheets (13), is formed. On the ceramic green sheet, an unfired boundary arranging conductor pattern (16) is arranged along the boundaries of the ceramic multilayer substrates (10a, 10b, 10c). The boundary arranging conductor pattern (16) has firing shrinkage behaviors different from those of the green sheet (13). When the unfired ceramic laminate (12a) is fired, spaces (18a, 18b) are formed at portions adjacent to the boundary arranging conductor pattern (16). A fired ceramic laminate (12b) is divided by a cut surface passing the spaces(18a, 18b).