A furnace for the thermal treatment of at least one dental firing object, comprising a housing, a firing chamber, a firing chamber base, a heating device, and at least one optical temperature detection element which can be used to detect a temperature in the firing chamber and is intended to enable a contactless temperature measurement of a dental firing object in a simple manner. This is achieved by virtue of the fact that the firing object is mounted on and/or in and/or below and/or alongside a firing aid situated in the firing chamber, and the optical temperature detection element detects the temperature of the firing aid.