In a bearing device 1 which is assembled to a pinion 3 of a rack-and-pinion type drive mechanism 2, the bearing device 1 has a plurality of needle rollers 13. A plurality of pin rollers 9 are supported by an inner surface cylindrically formed by the plurality of needle rollers 13. Each of the plurality of needle rollers 13 is held at both ends 13a, 13b in an axial direction R by a retainer cage 14, so as to prevent the needle rollers 13 from being skewed against the axial direction R.