A taper roller bearing includes an inner race, an outer race, taper rollers arranged so as to be rollable between the inner and outer races, and a retainer for retaining the taper rollers, in which a flange portion is provided only on the radially larger side of the inner race. The retainer includes a radially-larger-side annular portion including a hook portion. The hook portion effects hooking so that the flange portion of the inner race is maintained in an assembled state. In a neutral state, the hook portion is kept out of contact with the flange portion. A guide surface portion for guiding the inner race to be incorporated is provided on a radially inner end portion of an outer surface of the hook portion.