A bag is wheeled in an upright orientation on casters (1) on its bottom of by using a grip. A shaft (9) is coupled to a wheel (6) by one bearing (8). The ends of the shaft (9) are secured to the yoke (7) coupled to the bag portion (3). An outer ring (8B) of the bearing (8) is fitted in a fit-in groove (15) arranged at the center of the wheel (6). The outer diameter (A) of the shaft (9) is smaller than the inner diameter (B) of an inner ring (8A), and spacer pipes (17) are inserted into the inner ring (8A). Insertion portions (17B) of the spacer pipes (17) with a smaller outer diameter are attached to the inner ring (8A). Stopper portions (17A) with a greater outer diameter are arranged between the inner ring (8A) and the yoke (7) to hold the bearing (8).