PURPOSE: To obtain the title shelf device efficiently producing agar with little deformation by equipping a supporting frame with shelf stands in multiple stages rotatably and suspendibly in the longitudinal direction and furnishing each shelf stand with a net plate provided with a great number of pins on the top.

CONSTITUTION: A supporting frame having open front side and rear side is equipped with shelf stands 16 in multiple stages suspendibly in the longitudinal direction at a position inclining down forward, at a horizontal position or at a position inclining down backward and rotatably to manufacture a shelf device 10. Gelidium jelly with a proper size is pierced into a great number of pins 35 protrusively laid on the top of net plates 32 and arranged, the net plates 32 are introduced onto the shelf stands 16 at a horizontal position and the shelf device 10 is sent to a freezing chamber to freeze Gelidium jelly. Then the shelf device 10 is transferred to a thawing chamber and thawed, the shelf stands 16 are dried while changing the position inclining down forward and the position inclining down backward at proper time intervals to produce agar. Water dripped from the shelf stands 16 during drying is received on drain containers fixed to the shelf stands 16 and discharged to the outside.