A linear guide bearing device includes a rail, a bearing supported by the rail and rectilinearly movable along the axial direction of the rail, and rolling members interposed between the rail and the bearing to roll along with motion of the bearing. At least one of the rail and the bearing is made of induction-hardened steel including 0.6 to 0.9 wt % of carbon, 0.05 to 0.25 wt % of silicon, 0.3 to 0.9 wt % of manganese, 0.1 to 0.5 wt % of chromium, 0.2 to 1.0 wt % of molybdenum, and residual portion as iron and unavoidable impurities, and the induction-hardened steel has a total content of carbon, manganese, and molybdenum, which satisfies predetermined inequalities.