A supply apparatus for spout-equipped bags for supplying a plurality of spout-equipped bags through a plurality of transfer rails provided in parallel to a packing machine performing in parallel a predetermined packing to the spout-equipped bags, said supply apparatus for spout-equipped bags comprising: an intermittently conveying part sequentially conveying holding rails toward a predetermined taking-out position (c1a, c1b) in a direction orthogonal to a longitudinal direction of the holding rails at a predetermined interval P1, each of said holding rails providing with an engaging part being engaged on a flange portion (c01, c02, c03) of a spout-equipped bag, and holding a plurality of spout-equipped bags lined up in a row as the spout-equipped bags are hung; a pushing mechanism part pushing out the spout-equipped bags from the holding rails held on a predetermined transfer position (c2a, c2b, c2c, c2d), supplying the bags to the transfer rails; said supply apparatus characterized in that it further comprises: a plurality of conveying members (20, 21) taking out a plurality of holding rails conveyed to the taking-out position (c1a, c1b) and adjoining at the interval P1, transferring toward the transfer position (c2a, c2b, c2c, c2d); a driving mechanism part moving the conveying members (20, 21) between the taking-out position (c1a, c1b) and the transfer position (c2a, c2b, c2c, c2d); an interval change mechanism part being connected to the conveying members (20, 21), changing a relative interval of the transferred holding rails to a predetermined interval P2 in a transfer process by the conveying members (20, 21); a retention mechanism holding the holding rails transferred to the transfer position (c2a, c2b, c2c, c2d) on the transfer position (c2a, c2b, c2c, c2d) at the interval P2. an intermittently conveying part sequentially conveying holding rails toward a predetermined taking-out position (c1a, c1b) in a direction orthogonal to a longitudinal direction of the holding rails at a predetermined interval P1, each of said holding rails providing with an engaging part being engaged on a flange portion (c01, c02, c03) of a spout-equipped bag, and holding a plurality of spout-equipped bags lined up in a row as the spout-equipped bags are hung; a pushing mechanism part pushing out the spout-equipped bags from the holding rails held on a predetermined transfer position (c2a, c2b, c2c, c2d), supplying the bags to the transfer rails; said supply apparatus characterized in that it further comprises: a plurality of conveying members (20, 21) taking out a plurality of holding rails conveyed to the taking-out position (c1a, c1b) and adjoining at the interval P1, transferring toward the transfer position (c2a, c2b, c2c, c2d); a driving mechanism part moving the conveying members (20, 21) between the taking-out position (c1a, c1b) and the transfer position (c2a, c2b, c2c, c2d); an interval change mechanism part being connected to the conveying members (20, 21), changing a relative interval of the transferred holding rails to a predetermined interval P2 in a transfer process by the conveying members (20, 21); a retention mechanism holding the holding rails transferred to the transfer position (c2a, c2b, c2c, c2d) on the transfer position (c2a, c2b, c2c, c2d) at the interval P2. a plurality of conveying members (20, 21) taking out a plurality of holding rails conveyed to the taking-out position (c1a, c1b) and adjoining at the interval P1, transferring toward the transfer position (c2a, c2b, c2c, c2d); a driving mechanism part moving the conveying members (20, 21) between the taking-out position (c1a, c1b) and the transfer position (c2a, c2b, c2c, c2d); an interval change mechanism part being connected to the conveying members (20, 21), changing a relative interval of the transferred holding rails to a predetermined interval P2 in a transfer process by the conveying members (20, 21); a retention mechanism holding the holding rails transferred to the transfer position (c2a, c2b, c2c, c2d) on the transfer position (c2a, c2b, c2c, c2d) at the interval P2.