This invention relates to a continuous process for the preparation of carbon polymonofluoride.The reaction of fluorine diluted with at least one inert gas with carbon particles is performed in a reaction zone in which the particles travel as a thin layer. Diluted fluorine is introduced into the reaction zone in the form of a plurality of gaseous mixtures delivered at a plurality of points close to the layer of the particles and distributed in the reaction zone. The weight content of fluorine and the flow rate of each of the gaseous mixtures are controlled independently and such that the volume content of fluorine in the gaseous phase at the gaseous phase/particles interface in the vicinity of each of the points is lower than the minimum content causing the inflammation of the particles.For a space time output higher than 10 kg.h.sup.-1 m.sup.-3, the process permits a fluorine yield higher than 50% and capable of exceeding 60% to be obtained in the absence of recycling of the gases originating from the reaction zone.