PURPOSE: To simplify the installation work for a synthetic plate by fixing an inverted L-shaped metal fitting having a bolt for horizontal adjustment onto the back surface of the synthetic plate which is formed by attaching a natural stone thin plate and engaging the synthetic plate onto the backing horizontal member of a structure body by this metal fitting.

CONSTITUTION: A synthetic plate A is formed by superposition-attaching a natural stone thin plate 1 onto a ceramic group shaped plate, etc. A prescribed number of inverted L-shaped installation metal fitting 4 having each bolt 5 for the horizontal adjustment are fixed onto the back surface of the synthetic plate A. Further, a trunk edge member B is fixed horizontally through a pillar C onto a structure body W. An installation metal fitting 4 for the synthetic plate A is engaged with the trunk edge member B, and after the horizontal adjustment by the bolt 5, the installation metal fitting 4 is fixed. Therefore, the installation work for the synthetic plate A can be carried out easily by the common worker for the interior construction, obviating the need of work by a mason.