The invention relates to a heating unit for an inhalation device for the inhalation administration of an inhalation mixture of air and at least one additive material, having a fuel storage (252) which is filled or can be filled with a thermally combustible solid or liquid fuel (258), and with a combustion chamber (256) for the combustion of the fuel (258), which is essentially sealed from the surroundings by a combustion chamber wall (222). The invention further relates to an inhalation device (210) with such a heating unit.According to the invention, the combustion chamber (256) is designed for forming a flame, and the combustion chamber wall (222) has at least some micro openings (224). The micro openings are designed in such a way that the sum of the outer side lengths of all micro openings (224) is at least 140 mm, and the sum of the outer side lengths of the micro openings (224) per surface in the area of the combustion chamber wall (222) averages at least 80 mm/cm2.Application as cigarette substitute or as aid for nicotine withdrawal.