PURPOSE: To aim at simplifying the unfurling and furling steps of a jib which can be accommodated in a mast, by enabling the jib to be unfurled and furled with the use of a winch.

CONSTITUTION: A winch 5 is provided at the lower end of a mast 2 having a space for accommodating a sail, and is arranged to wind a rope 11 connected to the center part (d) and the corner part (b) of the sail and passing around pulleys 13a to 13d. Further, the winch is also applied to wind rope 8 which is connected to a slider 7 vertically movable along the mast 2 and attached to a corner part (a) in the sail and passes around pulleys 10a through 10f. When the winch is operated in the direction of arrow, wht center part (d) of the sail is pulled upward by the rope 11, and the slider 7 secured to the corner part (a) is simultaneously pulled upward, thereby the saild may be stored in the mast 2 by the rope 11.