PURPOSE: To reduce the weight of a laminated layer composite material and to perform a simple execution of works by forming the size of a natural stone plate in size of addition of the size of a wooden panel and a size larger than the thickness of a natural stone as a joining margin, and joining an another natural stone plate to the joining margin substantially in a T or L shape.

CONSTITUTION: A natural stone plate and a wooden panel of its core material are provided. The size of the stone plate has a joining margin 15 larger than the thickness of the stone plate in addition to the size of the core material. An another natural stone plate 12 and a wooden panel 22 from the first natural stone plate 11 and the wooden panel 21 are joined to the margin 15 substantially in an L shape. The plate 11 and the panel 21 are joined through an adhesive, and the plate 11 and the panel 21 are reinforced to be joined through the plate 12 and the panel 22, a square timer 4 (30×30mm) at the corners of the rear face side. Accordingly, since the natural stone plate has the margin 12 in addition to its size, a laminated composite material using the stone plate having a relatively reduced thickness and a light weight can be obtained.