A bag supply device (7, 31), used in a rotary bag-filling packaging machine equipped with a plurality of pairs of intermittently rotating grippers, disposed between a pair of grippers stopped at an empty bag supply position and an empty bag magazine device that holds empty bags, and receives empty bags one at a time from the empty bag magazine device, conveys an empty bag toward the pair of grippers stopped at the empty bag supply position, and converts the bag from a substantially horizontal orientation to a vertical orientation in a course of the conveyance to deliver the bag to the pair of grippers, wherein the plane of symmetry of the pair of grippers stopped at the empty bag supply position and the vertical plane including the center line passing through the center in the width direction of the empty bags stored in the empty bag magazine device intersect at a specific angle that is different from 0°; wherein said bag supply device (7, 31) comprises: an empty-bag holding member for holding or releasing an empty bag, a reciprocating mechanism for reciprocating the empty-bag holding member between a receiving position where the empty-bag holding member receives the empty bag and a delivery position where the empty bag is delivered to the pair of grippers, a first turning mechanism that turns the empty-bag holding member around a first axis (O 1) parallel to a bag width direction of the empty-bag holding member in conjunction with an operation of the reciprocating mechanism and orients a holding face of the empty-bag holding member vertically in the delivery position, characterized in that a second turning mechanism that turns the empty-bag holding member around a second axis (O 2) parallel to a bag length direction of the empty-bag holding member and causes the empty bag held by the empty-bag holding member in the delivery position to be directly across from the pair of grippers stopped in the empty bag supply position. used in a rotary bag-filling packaging machine equipped with a plurality of pairs of intermittently rotating grippers, disposed between a pair of grippers stopped at an empty bag supply position and an empty bag magazine device that holds empty bags, and receives empty bags one at a time from the empty bag magazine device, conveys an empty bag toward the pair of grippers stopped at the empty bag supply position, and converts the bag from a substantially horizontal orientation to a vertical orientation in a course of the conveyance to deliver the bag to the pair of grippers, wherein the plane of symmetry of the pair of grippers stopped at the empty bag supply position and the vertical plane including the center line passing through the center in the width direction of the empty bags stored in the empty bag magazine device intersect at a specific angle that is different from 0°; an empty-bag holding member for holding or releasing an empty bag, a reciprocating mechanism for reciprocating the empty-bag holding member between a receiving position where the empty-bag holding member receives the empty bag and a delivery position where the empty bag is delivered to the pair of grippers, a first turning mechanism that turns the empty-bag holding member around a first axis (O 1) parallel to a bag width direction of the empty-bag holding member in conjunction with an operation of the reciprocating mechanism and orients a holding face of the empty-bag holding member vertically in the delivery position, characterized in that a second turning mechanism that turns the empty-bag holding member around a second axis (O 2) parallel to a bag length direction of the empty-bag holding member and causes the empty bag held by the empty-bag holding member in the delivery position to be directly across from the pair of grippers stopped in the empty bag supply position.