A device for recovering floating materials on a liquid surface including: a float which is disposed inside a liquid layer where scum and oil are mixed and float, a recovery portion which recovers floating materials on the liquid surface which contain scum and oil floating on the liquid surface by a buoyant force of the float from a gate portion retained near the surface of the liquid layer, and a recovery pipe which is connected to the recovery portion, wherein the gate portion is installed at the recovery portion in a state capable of moving freely in a vertical direction and following vertical movement of the liquid level, and the float is arranged with a plurality of gate floats which are disposed around and in the vicinity of the gate portion to float and support the gate portion, thereby retaining the gate portion near the liquid level; a plurality of main floats which are disposed further outside than the plurality of gate floats to float and support the recovery portion and the recovery pipe connected to the recovery portion; the plurality of gate floats arranged so as to rotate around and in the vicinity of the gate portion, thereby raking/gathering to the gate portion liquid-level floating materials which come close to or float at a position in contact with the gate float, and each of the plurality of main floats is provided at an outer circumferential part in contact with the liquid level with one or a plurality of blade-like projections, and at least a part where the blade-like projection is installed is arranged to move rotationally or rotate along the liquid level, thereby crushing, separating and cleaving floating materials coming close to or floating at a position in contact with the main float; a driving device such as a motor for rotating the gate float and in which loads of the driving device are arranged to be supported by the main float; wherein each of the plurality of main floats is positioned so as to be lower than the liquid level, thereby realizing a vertical two-stage arrangement composed of a lower main float which mainly receives a buoyant force below the liquid level and an upper portion main float which mainly receives a buoyant force at the liquid level part by projecting partially above the liquid level; the blade-like projection is arranged so as to be installed at an outer circumferential portion of the upper portion main float; upon rotation of the gate float, at least a part of the gate float is in contact with the main float, thereby allowing the main float to move rotationally or rotate. a float which is disposed inside a liquid layer where scum and oil are mixed and float, a recovery portion which recovers floating materials on the liquid surface which contain scum and oil floating on the liquid surface by a buoyant force of the float from a gate portion retained near the surface of the liquid layer, and a recovery pipe which is connected to the recovery portion, wherein the gate portion is installed at the recovery portion in a state capable of moving freely in a vertical direction and following vertical movement of the liquid level, and the float is arranged with a plurality of gate floats which are disposed around and in the vicinity of the gate portion to float and support the gate portion, thereby retaining the gate portion near the liquid level; a plurality of main floats which are disposed further outside than the plurality of gate floats to float and support the recovery portion and the recovery pipe connected to the recovery portion; the plurality of gate floats arranged so as to rotate around and in the vicinity of the gate portion, thereby raking/gathering to the gate portion liquid-level floating materials which come close to or float at a position in contact with the gate float, and each of the plurality of main floats is provided at an outer circumferential part in contact with the liquid level with one or a plurality of blade-like projections, and at least a part where the blade-like projection is installed is arranged to move rotationally or rotate along the liquid level, thereby crushing, separating and cleaving floating materials coming close to or floating at a position in contact with the main float; a driving device such as a motor for rotating the gate float and in which loads of the driving device are arranged to be supported by the main float; wherein each of the plurality of main floats is positioned so as to be lower than the liquid level, thereby realizing a vertical two-stage arrangement composed of a lower main float which mainly receives a buoyant force below the liquid level and an upper portion main float which mainly receives a buoyant force at the liquid level part by projecting partially above the liquid level; the blade-like projection is arranged so as to be installed at an outer circumferential portion of the upper portion main float; upon rotation of the gate float, at least a part of the gate float is in contact with the main float, thereby allowing the main float to move rotationally or rotate.