To provide a scallop-culture cage so structured that a cross-in-square-shaped frame of the cage never breaks a raschel net thereof, nor a hanger ring thereof disturbs culture operations.

This scallop-culture cage is composed of the cross-in-square-shaped frame formed out of a square frame 6 and a cruciform frame 7 which are made of a plastic-coated iron wire, the pyramid-shaped plastic raschel net, and a hanger rope. The cross-in-square- shaped frame is formed by bending the wire to make it sides of the square frame 6 and connecting midpoints of the opposite sides of the square frame 6 by each of sides of the cruciform frame 7 so as to form a cross-in-square shape. The pyramid-shaped plastic raschel net receives the formed frame and makes the frame positioned on the inside bottom of the net. The hanger rope is so structured that the hanger ring is formed out of the rope and positioned above the center of the raschel net, the formed ring is connected to each of corners of the square frame 6 by the rope, and an intermediate of the rope is fastened to the intersection point of the cruciform frame 7. Further, a polymer of each of cut ends of the plastic- coated iron wires of the cruciform frame 7 is fused together with the polymer of thermoplastic resin, such as polyvinyl chloride (PVC), by dipping the cut ends of the wires into the fused thermoplastic resin, such as the fused PVC, so that the cut ends are each covered with the teardrop-shaped thermoplastic resin, i.e., a cut end-covering resin 8.