Abstract: A device for thermally killing weeds near plants of a valuable crop arranged in rows is provided with a frame which can be moved in the direction of the rows of plants, one or more burners fixed to the frame, the nozzles of which are directed at the ground or just above the ground, a discharge for combustion gases fitted at some distance opposite the burner nozzles, and a feed for feeding in cooling medium to form a cooling curtain at some distance above the place where the combustion gases of the burners will touch the ground. In order to kill only the weeds directly around the plant stems and also to prevent the combustion gases from flowing up along the plant stems, the outflow direction of the burners runs essentially at right angles relative to the direction of movement of the frame, and the discharge for discharging cooling medium are fixed to the frame at some horizontal distance opposite the cooling medium feed.