A screw top closure comprising a screw lid (10) with internal threading and a separate lid attachment (11) with external threading. The lid attachment (11) is designed for application on the neck (12) of a container (13) to carry the removable lid, the lid attachment (11) being in the form of an annular element with an upper part (14) serving as support for the lid (10), and two concentric tubular flanges (15, 16) protruding downwardly therefrom. These flanges between them in downward direction define an open pocket (17) for receipt of the neck (12) of the container (13). The lid (10) is provided with an inner tubular flange (25) protruding downwardly from an upper portion (21) thereof, the flange being insertable into the lid attachment (11) and designed to be brought into sealing abutment under pressure against the inner tubular flange (16) of the lid attachment (11) at a lower portion (16) thereof having reduced inner diameter in relation to the part of the flange (16) located above such that the inner flange of the lid attachment and the inner flange of the lid remain in sealing abutment with each other during partial unscrewing of the lid from the neck of the container.