PURPOSE: To provide movable decks folding device enables to load bulk cargo between the movable decks by enabling the movable decks to be folded at inclined position with an angle bigger than a resting angle of the bulk cargo.

CONSTITUTION: When hinge torque is exerted on a hinge 5, 5' after cargoes 7 on movable decks 8 - 13 are unloaded and a deck at middle portion of a hold is removed, link devices 15, 15' are folded and the movable decks 8 - 13 are folded and retained in inclined condition with an angle θ against level line. When bulk cargo 19 is loaded into a hold 20 through a hatch opening 17 subsequently, the bulk cargo 19 fills up spaces between movable decks 8 - 13 by gravity. The inclination angle θ of the movable decks 8 - 13 is set to be bigger than the resting angle of the bulk cargo 19, therefore, the bulk cargo 19 will flow down to the bottom of the hold by gravity upon unloading of the cargo 19.