To smoothly deliver a wire body into water without applying excessive tension to it by pressing gas into a storage section or a delivery path of the wire body, and delivering the wire body while keeping the gas pressure of the storage section at the liquid pressure or above of the water in which the wire body is delivered.

One end of a wire body F is delivered to the outside from a delivery pipe section 11, and a moving body is sunk in the sea while air is fed into the delivery pipe section 11 via a feed pipe section 12A by a compressor 3. The wire body F is delivered as the moving body is moved, and air is fed into the delivery pipe section 11 via the feed pipe section 12A by the compressor 3 at this time. The fed air flows in the delivering direction of the wire body F and is discharged into the sea from the tip of the feed pipe section 12A, and a storage section S and the delivery pipe section 11 are kept at the state filled with gas in them. The pressure of the storage section S is kept higher than the water pressure at the sea bottom where the wire body F is delivered.