A method of producing a composite sheet in which a through hole formed in a predetermined
portion of the first ceramic sheet is buried with a different kind of sheet having
substantially the same thickness as the first ceramic sheet, such as a resin sheet
a metal sheet or a ceramic sheet of a material different from that of the first
ceramic sheet. A first method comprises a step of preparing a first ceramic sheet
from a ceramic powder, and a different kind of sheet; a step of forming a through
hole in a predetermined portion of the first ceramic sheet; a step of laminating
the different kind of sheet on the ceramic sheet in which the through hole is formed;
and a step of preparing a composite sheet by pressing the portion of the first
ceramic sheet where the through hole is formed from the side of the different kind
of sheet, such that the first ceramic sheet and the different kind of sheet are
integrated together. A second method comprises a step of preparing a first ceramic
sheet and a different kind of sheet, and laminating the first ceramic sheet and
the different kind of sheet one upon the other; and a step of preparing a composite
sheet by pressing a predetermined portion of the laminate from the side of the
different kind of sheet, such that the pressed portion of the different kind of
sheet is transferred onto the side of the first ceramic sheet to integrate the
first ceramic sheet and the different kind of sheet together. A further method
is for producing a laminate by laminating the obtained composite sheet on other
first ceramic sheet or on other composite sheet.