PURPOSE: To efficiently press and dehydrate a green sheet to be continuously processed in the production of a planar building element in a flow-on system by a single pressing device.

CONSTITUTION: A slurry 1 is supplied onto a water permeable sheet 2 circulating in a fixed direction. The slurry 1 is dehydrated under reduced pressure by a suction means 11 provided under the lower surface of the sheet 2 for forming a continuous planar green sheet 3. The green sheet 3 is cut to a pre dimension, thereafter being cured to be used as a planar building element. In this equipment, above a cutting conveyor 5 disposed on the side of on the outlet of the sheet 2, a cutter for cutting the continuous planar green sheet 3 in its width direction is provided. Furthermore, at the outlet of the cutting conveyor 5, a separating conveyor 7 transporting the cut green sheet 3 at a speed higher than a transport speed of the cutting conveyor 5 is provided.