Ammonium dinitramide (ADN) is a new energetic material that can be used as an oxidizer in solid rocket propellants. In the last few years, a number of papers devoted to the study of ADN combustion mechanism have been published. Molecular beam mass-spectrometry and thermocouple measurements are here used to study ADN flame structure at pressures of 0.3 and 0.6 MPa. Measurements include species concentrations and temperature profiles. A general mechanism for describing the chemical reactions in an ADN flame (172 reactions and 31 species) is developed based on these experimental studies and literature data. The scheme includes a sub-mechanism (98 reactions and 22 species) for propellants combustion suggested by Yetter and Dryer. The latter is further supplemented by a set of 74 reactions. including 63 steps suggested by Lin and Park and the ADN dissociation reactions suggested by the authors of this paper. The correlation between the experimental and calculation results is satisfactory.