The present invention relates to a batch furnace for annealing material comprising a furnace housing which has a closable loading opening, a receiving chamber for furnace material and a device for convective heat transfer to the furnace material by a heat transfer medium, wherein the device for convective heat transfer comprises at least one heating device and at least one fan which is arranged in the furnace housing wherein the receiving chamber is arranged on the suction side of the fan and at least one nozzle array is arranged on the pressure side of the fan, wherein the nozzle array has a central opening which forms an intake duct of the fan and the nozzle array projects radially beyond the fan. The invention further relates to a method for heat treatment of a furnace material.