PURPOSE: To prevent a resin sheet from sagging, by supporting the sheet by a sheet receiving belt while the forward movement of the sheet in front of a molding apparatus is suspended when the sheet that has been continuously fed is intermittently conveyed to the molding apparatus.

CONSTITUTION: A pair of clamping chains 6, which are driven circularly to travel linearly from forward to backward of the molding machine 1, and the sheet receiving belt 24, which is driven circularly to travel linearly at the same rate as the chains 6 in front of the molding machine 1 toward just before the molding machine 1, are provided. The opposite sewages of the continuously fed resin sheet (a) that has been solftened by heating it to a suitable molding temperature are bit at the forward end of the horizontal traveling section by the chains 6 that are driven at a rate synchronously with the feeding rate of the sheet, and at the same time the sheet surface except the sewage is supported by the belt 24, so that when molding operation is carried out, the movement of the sheet (a) is stopped to prevent the sheet (a) from sagging due to thermal deformation, and when the molding operation has been finished, the stopped sheet (a) is disengaged from the belt 24 thereby the sheet (a) is intermittently fed to the molding apparatus 1.