a first conveyor configured to transfer an empty packing box, an upper surface of which is opened, from a withdrawn position at which products are withdrawn from a packing box to a reversed position at which a reversing operation is performed;

a turning device configured to hold the packing box to be turned about a rotation axis horizontal to the ground, and to reverse the packing box; and

a second conveyor configured to carry the packing box to a position at which a work of opening a bottom surface is conducted,

wherein the turning device holds two sides, facing each other, among sides of the packing box, and causes the packing box to be turned and reversed using a portion between holding locations of the two held sides as a rotation axis,

wherein an upper surface panel covering the upper surface of the packing box is provided on the upper surface of the packing box, and introduced into the reversing system in an unfolded state when the products are withdrawn, wherein the upper surface panel comprises a pair of first upper surface panels facing each other and a pair of second upper surface panels that are disposed perpendicular to the first upper surface panels and face each other, and

the turning device comprises a movable frame moved upwardly and downwardly at the reversed position, a pair of suction units that are disposed at positions facing each other, respectively and having suction members that are actuated to move toward or away from each other and that draw the sides of the packing box at an approximating time, and bars configured to bring the upper surface panel of opened and unfolded state into close contact,

the bars comprise a plurality of bars extending in parallel with drawing directions of the suction members, each of the bars coming into contact with each of the first upper surface panels and bringing the first panels in contact with the packing box by a downward movement actuation, and

each of the suction units provided with mounting panels to which the suction member s are attached, and each of the mounting panels brings a leading end thereof in close contact with each of the second upper surface panels and brings the second upper surface panels into close contact with the side of the packing box by the downward movement actuation,

wherein each of the suction units is provided with a plurality of the suction members, and the suction members disposed on a side below the turning axis come into contact with the side of the packing box, and the suction members disposed on a side above the turning axis come into contact with the second upper surface panels of the packing box, and

wherein the mounting panels are moved in the directions approximating each other as linear actuators are enlarged and actuated.