A hot-pressing tool mounted on a press and operable under a controlled atmosphere, a method for implementing such a hot-pressing tool, and a facility for manufacturing objects that includes such a hot-pressing tool. The tool includes a first tool portion having a first fastening device to fasten onto a first platen, a second tool portion having a second fastening device to fasten onto a second platen. The first fastening device and the second fastening device are mobile with respect to one another to define a pressing chamber having an inner volume which is heated via a heating device. The first fastening device and the second fastening device each respectively have a pressing member to exert a pressing force on opposite faces of an object to be pressed in the pressing chamber. The heating device is to heat via optical radiation that is concentrated on the object via a concentration device.