<p>A roller bearing formed by interposing spacers between rollers which enables the smooth flow of a lubricant near the rolling surfaces thereof to reduce the agitating resistance of the lubricant by the spacers so that a higher allowable rotating speed can be attained. The roller bearing comprises the plurality of rollers (16) rollably interposed between the inner ring raceway surfaces and the outer ring raceway surfaces thereof and the spacers (18) between the adjacent rollers (16). Each of the spacers (18) comprises extension parts (18a) facing the end faces (16b) of the roller at both ends in the axial direction.</p>
