A gripper device used in a bag filling and packaging machine and moved, while holding a bag, along a predetermined path to change the orientation of the bag, the gripper device including: a movable frame (2) that is moved along the predetermined path in a horizontal plane, a pivot frame (3) that is pivotably supported by the movable frame and has a horizontal pivot axis (O1), a pair of gripper arms (4, 5) that are pivotably supported by the pivot frame and pivoted, in conjunction with each other, symmetrically in a plane parallel to the pivot axis of the pivot frame, a bag orientation changing mechanism (14) that is installed on the movable frame and pivots the pivot frame at an angle of 90°, and a gripper arm pivot mechanism (15) that is installed on the movable frame and pivots the pair of gripper arms.