Abstract: The invention relates to a lid (1) and a method of opening the lid which is used for closing a container (15) having means on the inner side of screwing on to the neck (2) of a container. Internally, the lid has an inner lid (5) which is secured in the lid (1) by at least one securing means. The object of the invention is to provide a lid which is easy to open without using a great force or by using a tool, and which may simultaneously be disposed of without significant environmental impact. This is achieved by a lid (1) whose collar (3) has at least one projection (13) which points radially toward the centre and which extends from the inner side of the collar (3), wherein, during unscrewing of the lid (1), the projection (13) presses the edge of the inner lid (5) at least at one point out of contact with the upper edge of the package neck. This ensures venting of the volume of the container with a relatively weak torque.