Abstract: A roller guide apparatus comprises: a track rail comprising a rail body extending in a longitudinal direction thereof and having a section in a width direction thereof in shape of circular arc protruding downward in an installed state and a base portion supporting a lower surface of central portion of the rail body in the width direction thereof, the rail body having an upper surface and lower surfaces extended in the width direction from the base portion, the upper and lower surfaces of the rail body having concentric circular arc shapes; a movable block body comprising a block body arranged so as to straddle the rail body and having a lower surface, in an assembled state, opposing to the upper surface of the rail body, a pair of bilateral leg portions extending downward from bilateral end portions of the block body with the track rail being interposed therebetween, a pair of support piece portions extending towards the track rail so as to oppose to the extended portions of the rail body; at least one barrel