PURPOSE: To uniformalize the board thickness of a green sheet as much as possible to improve a product quality in the production of a planar building element in a flow-on system by providing an adjusting means adjusting a slurry supply thickness to a sheet on the basis of a detection value of a measuring means measuring the board thickness of a green sheet piece.

CONSTITUTION: In a production equipment for a planar building element, a junction conveyor 7 for transporting a green sheet piece 6 formed by cutting a green sheet 3 at a prescribed position in its forward direction is provided on the side of the outlet of a sheet 2; a take-off conveyor 22 for respectively delivering the green sheet piece 6 to a pressing device 8 is provided at the outlet of the junction conveyor 7; a measuring means 26 measuring the board thickness of the green sheet piece 6 transported from the junction conveyor 7 to the take-off conveyor 22 is provided and based on the detection value of the measuring means 26, the supply thickness of the slurry 1 to the sheet 2 is adjusted by an adjusting means 9A. Therefore, even if the green sheet piece 6 is fluctuated in board thickness in a cutting process or a transporting process, a slurry supply thickness to the sheet 2 is adjusted based on board thickness data containing this fluctuation.