To provide an oil boom supporting structure which can surely prevent spilt oil from leaking by allowing an oil boom body and its supporting body to move up and down freely in a manner of following a draft line of a ship body so that the performance of following the fluctuation of the draft line of the ship body may be improved.

The oil boom supporting structure comprises (1) a magnetic roll holding body provided with a plurality of magnetic rolls and a floating body arranged to face the wall surface of a structure, and (2) the oil boom body attached to the magnetic roll holding body. Further, (3) the oil boom supporting structure is made to be movable up and down by the magnetic roll in a manner that the supporting structure automatically follows the draft line by the buoyancy of the floating body when the draft line goes up and by the self-weight of the magnetic roll holding body and the oil boom body when the draft line goes down.