The invention relates to a lid (100) of a container, especially a beverage can, comprising a substantially flat lid surface (101) and a preferably folded edge area (102), and at least one pouring opening (103) arranged on the lid surface (101), which pouring opening can be closed in a gas-tight and/or fluid-tight manner by way of at least one closure element (120) arranged in the region of the underside of the lid surface (101) facing the interior of the container, with the closure element (120) being movable from a closed position to an open position by an actuating element (110), and at least one pressure equalizing device is provided which cooperates with the at least one actuating element (110), wherein the at least one pressure equalizing device comprises at least one closing element (112, 113), and at least one pressure equalizing opening (123) is provided which is closeable by means of the at least one closing element (112, 113, 114) when the actuating element (110) is in the closed position and can be exposed entirely upon moving the actuating element (110) from the closed position to the open position, with the exposure of the pressure equalizing opening (123) being reversible.