A self aligning roller bearing with retainer comprises an outer ring having an outer ring raceway in a shape of a spherical concave surface with a single center, an inner ring having a pair of inner ring raceways opposite to the outer ring raceway, a plurality of convex rollers provided rotatable between the outer ring raceway and the inner ring raceway, and a pair of retainers comprising a main portion formed in a hollow cylindrical frustum shape and having a plurality of crossbars, an outwardly flanged portion extending radially outward from the larger diameter end of the main portion and an inwardly flanged portion extending radially inward from the smaller diameter end of the main portion, and connected to the outwardly flanges portion by the crossbars so as to form a plurality of pockets each defined by two of the crossbars and outwardly and inwardly flanged portions to receive one of the convex rollers, the outwardly flanged portion having protrusions each protruding towards the pocket so as to rub against or be in close proximity to the first end face of the convex rollers, and the protrusions having an end face for guiding each of the convex rollers retained inside the respective pockets.