The invention relates to a cleaning lance comprising a jet pipe (1) whose output end is provided with a jet nozzle (2) switchable between high- and low-pressure positions my means of a switching mechanism. The aim of said invention is to develop a cleaning lance which makes it possible to use foam as high-pressure washing devoid of necessity to manually switch the operating mode directly on the lance. The jet pipe (1) is provided with an air inlet (3) closable by a valve (4), wherein the valve function is coupled with the switching mechanism of the jet nozzle (2) in such a way that the valve (4) closes the air inlet (3) when said jet nozzle (2) is switched from the low-pressure position to the high-pressure position thereof.