PURPOSE: To facilitate the accommodation work for rolling bodies and simplify the assembly of a unit by constituting a sliding board by joining a pluraliry of divided bodies each having a circulation passage forming surface forming a rolling body circulation device through joining.

CONSTITUTION: A direct acting guide unit is constituted of a U-shaped track rail 1 having the section which is vertical to the longitudinal direction and is opened upwardly, rolling body circulation passage consisting of a load track groove, return passage and a direction change passage, and a sliding board 3 which can be relatively shifted for the track rail 1. Further, a number of rollers 5 are arranged as the rolling body for applying a downward load between the track rail 1 and the sliding board 3. The track rail 1, sliding board 3, and the roller 5 are made of resin, and the track rail 1 is formed integrally, and the sliding board 3 is formed by joining the left and right divided bodies 7 and 8. Each divided body 7, 8 has a circulation passage formation surface forming a rolling body circulation passage 2 by joint, and the circulation passage formation surface has a groove part corresponding to the projection part 5a of the roller 5.