Abstract: The high efficiency solid fuel combustion apparatus comprises a thermally insulated wall structure defining an upwardly open primary combustion chamber, a solid fuel support disposed within the primary combustion chamber, and a secondary combustion air supply device mounted on top of the primary combustion chamber. The secondary air supply device comprises a frusto-conical shell open at both axial ends and oriented with its larger axial end opening to the primary combustion chamber. The shell has spaced inner and outer walls defining a frusto-conical air space there between, with the inner and outer walls being circumferentially sealed to one another and the inner wall being perforated for expelling secondary combustion air into the pyrolytic gasses generated by the burning fuel in the primary combustion chamber.