Abstract: A description is given of a cyclone burner for converting solid fuel comprising a substantially rotationally-symmetric whirling chamber (1), means for introducing gas and fuel into the whirling chamber (1), means for bringing the gas and fuel into rotation in the whirling chamber (1) and an outlet (4) for the gas and the converted fuel where the outlet (4) is centrally positioned in the outlet end (3) of the whirling chamber (1). The cyclone burner is characterized in that the whirling chamber (1) comprises a conical shaped portion (2) having the smaller diameter furthest from the outlet end (3) and in that the means (5) for introducing gas are connected to the whirling chamber (1) along the length of the conical shaped portion (2).