a guide apparatus includes a track rail having raceway surfaces for rolling elements formed longitudinally , a slider having a load raceway surface opposing the raceway surface and a return path for rolling elements disposed in parallel with the load raceway surface , and having paired reversal - of - direction paths completing an endless circulation path for rolling elements by connecting the load raceway surface with either end of the return path and is attached to the track rail to enable their relative movement , and plural rolling elements susceptible to load at a position between a load raceway surface of the slider and the raceway surface of the track rail and circulating in the endless circulation path . a step where the load raceway surface becomes lower than a sidewall surface at an inner diameter of the reversal - of - direction path is formed at a location where the reversal - of - direction path is connected to the load raceway surface .