The invention relates to a plastic enclosure for enclosing industrial components. The enclosure comprises a case (2), a lid (9), and a latch device (13) for locking the lid to the case. The lid (9) has a grip means formed as a rigid lug (14) molded to be monolithic with the lid (9), the lug comprising a throughhole (19) to which a hook portion (17) of a rocker (15) can grip. The lug (14) is arranged, in the closed position of the lid, to extend over and at a distance from the second wall (7) to be substantially in parallel with a wall of the case to limit an intermediate space between the wall (7) and the lug (14) when the lid is in the closed position. The hook portion (17) is arranged so that, in the release position (II) of the rocker (15), it is turned inside the intermediate space away from the path of the lug (14) and, in the locking position (I) of the rocker, the hook portion is turned to protrude laterally outwards through the through-hole (19) of the lug (14) and to compress the sealing gasket (12) by pressing the sealing flange (8) against the sealing gasket (12) to create a spring force against which the hook portion holds the lug (14). The output force of the hook portion (17) exerted to the lug (14) is amplified by a mechanical advantage provided by a lever effect of the rocker (15) when being turned to the locking position by an input force exerted to the handle arm (18).