Objects of the present invention are to provide a low-temperature co-fired ceramic material having a coefficient of linear thermal expansion controlled and has a high dielectric constant, and to reduce the warpage of a fired product even if it has an unsymmetrical lamination structure in a multilayer wiring board in which glass-ceramic mixed layers of different compositions are laminated.A low-temperature co-fired ceramic material in accordance with the present invention includes: SiO.sub.2--B.sub.2O.sub.3--Al.sub.2O.sub.3-- alkaline earth metal oxide based glass, alumina, titania, and cordierite; glass, titania, and cordierite; or glass, titania, and mullite. When a multilayer wiring board is made of the low-temperature co-fired ceramic material, the content of cordierite or mullite of the substrate material is adjusted to control a difference in a coefficient of linear thermal expansion between the layers of the substrate material to not more than 0.25.times.10.sup.-6/.degree. C.