Provided is a cage unit including a cage having a small diameter side annular portion, a large diameter side annular portion arranged so as to be spaced apart in an axial direction from the small diameter side annular portion, and a plurality of cage bar portions that connect the small diameter side annular portion and the large diameter side annular portion; and a tapered roller accommodated in a pocket, which is a space surrounded by the small diameter side annular portion, the large diameter side annular portion, and the cage bar portions. A lubrication groove lying along a circumferential direction is formed on an inner end face of the large diameter side annular portion that faces a roller large end face of the tapered roller, and a circumferential length of the lubrication groove is designed such that the lubrication groove overlaps the roller large end face in the circumferential direction.