To provide an economically excellent apparatus which can perform bundling according to ability of a production line and does not need large-scale mechanization or large modification of an existing line in feeding and bundling hoops to a coil.

In an operation of radially tying with a hoop 6 through an inner diameter of a coil or peripherally tying the coil 8 with the hoop 6, the apparatus includes a retractor 7 of the hoop 6, a cutter 2, a guide 3 for shaping the hoop into a U-shape and hoop clamping mechanisms 41 and 42. Operations of holding a tip of the hoop 6 shaped by the guide 3, forming the hoop 6 of a length according to a thin plate coil 4 to be bundled into a loop, and cutting it are repeated, thereby preparing a plurality of hoops 6 required for bundling. The hoops 6 are together supplied to a bundling section of the coils 8 by a rotary table 54 and rising/lowering and horizontally sliding mechanisms 56 and 52.