Abstract: A plant for retorting oil products contained in shales and sands comprising a continuous retorting in a substantially horizontal retort furnace having any cross-section, into which said shales and sands are introduced by means of hoppers and metering devices and placed on metal conveyors moving in counter-current to gases, means being provided for placing said shales and sands onto said conveyors with a suitable thickness and for stirring the shales and sands, one or more combustion chambers arranged outside said retort furnace, in which hot gases are produced, and one or more input zones along the retort furnace for the admission of hot gases into the retort furnace which hot gases mix with pre-heated circulating gases at the expenses of the sensitive heat of the exhausted shale and sand material, a direct contact condenser at the furnace head, provided for condensing distilled oil products by a cold fluid and a decantation tank arranged beneath said condenser for depurating the process gases from the dust.