To provide a laminating apparatus and method that enable one to reduce the amount of warping of the workpiece (10) considerably during heating at the laminating section in comparison with conventional methods. The laminating apparatus (100) is used in the laminating method where internal filling material is melted by heating, wherein an apparatus (100) is equipped with a laminating section that has upper and lower chambers (113,121) separated by a diaphragm (112). The workpieces (10) which are ready to be transported to the laminating section described above is preheated by plural pre-heaters (250).