A linear guide apparatus has a rail having a rail side rolling element raceway groove, a slider having a slider side rolling element raceway groove, pluralities of rolling elements disposed between the rail and the slider, a rolling element return path in the slider, a curved path in an end cap attached to both ends of the slider and a crowning portion provided at both ends of the slider side rolling element raceway groove and having an effective crowning part like a curved surface and extending continuously from the slider side rolling element raceway groove and an out-of-effective crowning part like a curved surface and extending continuously from the effective crowning part, wherein the effective crowning part has a larger curvature radius so that a slope thereof is gentle, while the out-of-effective crowning part has a curvature radius smaller than that of the effective crowning part.