Abstract: Installation for the drying, heating, sterilization or disinfection of dry, moist or wet materials or materials in a moist environment and of liquids, particularly waste which may be infected, e.g., medical waste, in which the materials to be treated are introduced into a microwave-permeable vessel in a pressure-proof treatment space which can be acted upon by microwaves and sealed in a pressure-tight manner, wherein a plurality of magnetrons are coupled into the resonant space forming the treatment space in such a way that microwave dead spaces are prevented, wherein the physical parameters in the device are monitored and utilized for controlling the installation, and wherein added units are also provided for influencing the course of the process.