Abstract: Oven for charring plant matter, downdraft intermittent operation type, without external energy source. The invention relates essentially to the arrangement of the hearth located at the bottom of the oven, which provides the mechanical stability of the whole, the distribution of fresh air by means of a device permitting the circulation of air on the inside, as well as the precise control of its admission and airtight sealing at the end of the cycle; the collection of gases and pyroligneous liquors by means of an annular collector terminating in a single flue. The pyroligneous liquors are collected at the bottom of the flue. A condenser maybe installed to recover tars or to provide complete processing of the gases. Removal of the charcoal by gravity through a central opening, the cover of which contains the closable lighting aperture.