Abstract: An improved apparatus for forming an elongated synthetic resin plate or sheet, is provided. The lower steel belt of the apparatus is placed on a lower board and is intermittently fed by a predetermined distance. Side frames are installed on the lower steel belt, the side frames stretching on both the right and left edges of the lower steel belt in the lengthwise direction thereof. The upper steel belt is disposed between the two side frames, and an upper board is installed on the upper steel belt. Either one of the upper board or the lower board is so constructed as to be movable up and down. The resinous starting material is pressed by the pressing operation of the board which moves up and down via the upper and lower steel belts. The upper and lower boards are divided into a plurality of blocks so as to correspond to the opposing ones, thereby to constitute heating zones having heating means and cooling zones having cooling means.