A guide apparatus has a standard end plate split into a pair of split parts that can be positioned with respect to each other with high accuracy and firmly secured to each axial end of a moving block body without fear of displacement during use. The guide apparatus has a moving block relatively movably attached to a track rail. The moving block body has in a section perpendicular to the axial direction a geometry that allows the moving block body to be assembled to the track rail at an intermediate part of the track rail. The end plate consists essentially of a pair of split parts that are splittable to right and left in the width direction of the end plate. One split part has a positioning pin projecting from a parting surface thereof. A positioning hole fittable with the positioning pin is provided in a parting surface of the other split part. The positioning pin is fitted into the positioning hole to form an end plate assembly. The end plate assembly is secured to one end of the moving block body in the direction of relative movement by using securing screws passed through securing screw holes provided in the split parts, respectively.