Abstract: A chamber serving for a heat treatment of a particular food product, which for example can be pre-processed potato pieces which are to be prepared as French fried potatoes, and therefore have a content of evaporable substances, such as fat. In the chamber is a grid for, during operation, carrying the product, and one or more quartz lamps for generating heat for the process. The chamber is furthermore fitted with an exhaust channel which via a filter device connects the chamber to the open. Above the grid is placed a cabinet which is open at the bottom, for mounting the quartz lamps. The cabinet is via an inlet duct connected to the open. In the inlet duct is placed a ventilator for sending an air flow into the cabinet via the inlet duct. The air acts as a shield which keeps for example fat vapors at a distance so that they cannot come into contact with the quartz lamps and disintegrate in the high temperature of these.