Door system for an elevator installation comprising an elevator cab, the door system comprising: a pivotable first cab door leaf, and a pivotable first shaft door leaf, it being possible to mount the first cab door leaf at a cab door opening of the elevator cab and to mount the first shaft door leaf at a shaft door opening of the elevator installation, it being possible to close at least part of the shaft door opening by means of the first shaft door leaf in the closed position thereof, and a shaft door plane being formed along the shaft door leaf that can be arranged in the closed position thereof, it being possible to close at least part of the cab door opening by means of the first cab door leaf in the closed position thereof, and a cab door plane being formed along the cab door leaf that can be arranged in the closed position thereof, the cab door leaf, in the open position thereof, passing through the shaft door plane, or the shaft door leaf, in the open position thereof, passing through the cab door plane, it being possible to mount the first cab door leaf on a main pivot axis that is arranged on the elevator cab and to mount the first shaft door leaf on an additional main pivot axis, the main pivot axis associated with the cab door leaf being arranged in parallel with the main pivot axis associated with the shaft door leaf, the door system - comprising a second cab door leaf, which second cab door leaf is pivotally mounted on a secondary pivot axis on the first cab door leaf such that the first and the second cab door leaf (20, 21) form a folding door, and - comprising a second shaft door leaf, the second shaft door leaf being pivotally mounted on a secondary pivot axis on the first shaft door leaf such that the first and the second shaft door leaf (22, 23) form a folding door, the secondary pivot axes (25, 27) being arranged in parallel with the main pivot axes (24, 26), characterized in that the first shaft door leaf and the first cab door leaf are arranged so as to be directly stacked together in the open position thereof, and the second shaft door leaf and the second cab door leaf being arranged so as to be directly stacked together in the open position thereof. a pivotable first cab door leaf, and a pivotable first shaft door leaf, it being possible to mount the first cab door leaf at a cab door opening of the elevator cab and to mount the first shaft door leaf at a shaft door opening of the elevator installation, it being possible to close at least part of the shaft door opening by means of the first shaft door leaf in the closed position thereof, and a shaft door plane being formed along the shaft door leaf that can be arranged in the closed position thereof, it being possible to close at least part of the cab door opening by means of the first cab door leaf in the closed position thereof, and a cab door plane being formed along the cab door leaf that can be arranged in the closed position thereof, the cab door leaf, in the open position thereof, passing through the shaft door plane, or the shaft door leaf, in the open position thereof, passing through the cab door plane, it being possible to mount the first cab door leaf on a main pivot axis that is arranged on the elevator cab and to mount the first shaft door leaf on an additional main pivot axis, the main pivot axis associated with the cab door leaf being arranged in parallel with the main pivot axis associated with the shaft door leaf, the door system - comprising a second cab door leaf, which second cab door leaf is pivotally mounted on a secondary pivot axis on the first cab door leaf such that the first and the second cab door leaf (20, 21) form a folding door, and - comprising a second shaft door leaf, the second shaft door leaf being pivotally mounted on a secondary pivot axis on the first shaft door leaf such that the first and the second shaft door leaf (22, 23) form a folding door, the secondary pivot axes (25, 27) being arranged in parallel with the main pivot axes (24, 26), - comprising a second cab door leaf, which second cab door leaf is pivotally mounted on a secondary pivot axis on the first cab door leaf such that the first and the second cab door leaf (20, 21) form a folding door, and - comprising a second shaft door leaf, the second shaft door leaf being pivotally mounted on a secondary pivot axis on the first shaft door leaf such that the first and the second shaft door leaf (22, 23) form a folding door, the secondary pivot axes (25, 27) being arranged in parallel with the main pivot axes (24, 26), characterized in that the first shaft door leaf and the first cab door leaf are arranged so as to be directly stacked together in the open position thereof, and the second shaft door leaf and the second cab door leaf being arranged so as to be directly stacked together in the open position thereof.