An apparatus for repeatedly applying seals on the opening of bottles or similar containers comprising: at least one applicator head (2,3), having a cavity, or a notch (4) whose shape is complementary to the opening (21) of the bottle (15) ; the operating head comprises at least two rigid members (2,3) being movable relatively to each other for clamping a segment of tape (1,16) between them whereas said members (2,3) have at least one trough hole (4) having a diameter longer than that of the edges of the openings (21) to be sealed; means for feeding the tape (1,16) between said rigid members (2,3); means for relative motion along the axes of the notch (4) or opening (21) of the applicator head (2,3) and of the bottle or container (15), in the two directions wherein the notch is fitted closely on the opening zone (21) and the applicator head (2,3) is displaced from said opening (21); means for feeding and for positioning a succession of bottles (15), one after the other, with their opening (21) facing the notch (4) of the operating head (2,3); said gripping members (2,3) being slidably movable along guide means (7) and guides (8), in such a way that the two gripping member (2) firstly clamp the tape and then execute a common displacement relative to the bottle (15) for drawing on its opening the tape (1,16).