<p>Results of numerical simulation of the nonstationary temperature field of a shaft-type furnace, designed for the melting of glass and the production of glass wares, are presented. A thermal model of the operating furnace and of its subspace was constructed, and the heat links in the furnace and the methods of their calculating were determined. Basic relations and formulas, comprising a mathematical model of the nonuniform, nonstationary temperature field of this furnace, were derived. A software has been developed for the numerical simulation of the temperature field of the furnace in a wide range of change in its design parameters. A good agreement was achieved between the numerical simulation results and the temperatures measured in the furnace in the process of production of glass wares in it. It was established that the stability of the temperature in the zone of formation of a glass ware in the furnace depends substantially on the position of a control thermocouple in it.</p>