<；P>；PROBLEM TO BE SOLVED: To provide a substrate unit for deposition which hardly disturbs sunshine, hardly forms spaces among filling materials, and prevents the filling materials from being moved, and to provide a construction for growing floating larva, using the unit. <；P>；SOLUTION: The substrate unit 1 for the deposition, using the floating larvae as the substrate to be deposited includes a flexible bag net (2) obtained by forming a net having a prescribed mesh size into a bag shape, the filling materials (3, 31) formed of aggregates of inorganic solid materials having a size not dropping from the mesh, and packed in the bag net, and a tightening unit for tightening the bag net to prevent the filling materials from moving in the interior of the net bag. The tightening unit is a rope which is wound around the outer periphery of the bag net and penetrated into the interior of the bag net, and is tensed. <；P>；COPYRIGHT: (C)2010,JPO&INPIT
