A roller bearing includes: an inner ring having an inner ring raceway; an outer ring having an outer ring raceway; and a plurality of rollers interposed between the inner ring raceway and an outer ring raceway, wherein a crowning is formed on at least one of the inner ring raceway, the outer ring raceway, and a roller rolling contact surface, wherein an optimal value of a drop amount of the crowning at an end of an effective length is determined, from a diameter of a roller and an effective length of the roller, and wherein drop amounts of the crowning at a plurality of positions in a bus-line direction of the crowning are within an allowable range set forth in a specific table.