A heating muffle for a muffle kiln for the production of a dental ceramic product containing titanium, which comprises a hollow unit, which is provided with at least one opening for the uptake of the ceramic product and has completely heatable inner walls, an which can form together with a pedestal a firing chamber in which the ceramic product is heated by the inner walls, wherein the hollow unit comprises at least one spirally bent tube containing a heat conductor for a uniform heat transfer to the product and in order to avoid temperature gradients.