Operating element of powder gas actuated tools and equipped with a combustion chamber, wherein the element is of a cylindrical shape, and in the internal chamber of the cylindrical body (1), there is a displaced piston (2) located and equipped with the arbour (3) surrounded by a return spring element (4); however, the arbour (3) is terminated with a replaceable operating bit (5), and the return spring element (4) is supported with one end of the piston (2) and with the other on the bottom (6) of the cylindrical body (1), which has a port hole, in which the arbour (3) is guided.