An object of the present invention is to prevent breakup of segments which constitute a split type retainer for a tapered roller bearing, when the tapered roller bearing is being mounted on target equipment, thereby improving operability in the mounting process. A segment for a tapered roller bearing is provided with a predetermined number of posts between a small-diameter-side end fringe which constitutes a small-diameter-side circumferential edge of a split type retainer and a large-diameter-side end fringe which constitutes a large-diameter-side circumferential edge thereof. Pockets are formed between the posts. At least the large-diameter-side end fringe, out of the small-diameter-side end fringe and the large-diameter-side end fringe, is provided with a large-diameter-side engagement piece. When the bearing is mounted, the large-diameter-side engagement piece is engaged with the large-diameter engagement member fitted and fixed onto the bearing's inner ring, whereby the segment is prevented from breaking up.