Abstract: A board press consisting of a plurality of press plates placed one above the other and which are pressed together with the aid of pressure cylinders when pressing boards, and said press plates being interconnected with a simultaneous apparatus which maintains equal distances between press plates during movement of the press plates. The simultaneous apparatus consists of lever units at a plurality of points on both longitudinal margins of the press plates, which have been interconnected to constitute one simultaneous unit, with the aid of a rod pivotally attached to each press plate and a lever arm on the other end of said rod and a transversal turning shaft common to each pair of lever units and control rods longitudinal to the apparatus.