To reduce friction loss, and to prevent deterioration of rolling service life due to abrasion by preventing an edge load.

In a rocker arm 12 of the roller rocker arm type valve gear 10, a roller 24 is turnably supported by a roller pin 26 via a plurality of needle rollers 22. A diametrally enlarged part 30 with a diameter enlarging from a roller 24 width direction center part side toward both end part sides is formed on roller 24 width direction both ends in an inner circumferential face of the roller 24. When there is an error of alignment during manufacture, or due to operating conditions or the like, and an outer side roller 24 is tilted by abutting with a cam, edge loads tend to occur in respective axial (a roller 24 width direction) end parts of the inner circumferential face of the roller 24, and the plurality of needle rollers 22. But, since the diametrally enlarged part 30 is formed on the roller 24, even if the roller 24 is tilted, the edge loads do not increase in the axial end parts of the inner circumferential face of the roller 24, and the plurality of needle rollers 22.