Sealing member and the linear motion guide apparatus using the same

A ball screw mechanism or a linear motion guide device is provided which has a sealing element, can surely prevent dust and dirt in a movable element of a linear motion guide device from an outside penetrates it, and which has a high dust sealing function of high sealing efficiency, the fine dust, dirt or the like can securely seal by contacting a secure seal to a shaft member without providing a large margin of the seal. The sealing member includes a body portion that is mountable to the movable member, and a lip portion which contacts an outer peripheral portion of the shaft member, the lip portion is provided with an inclined surface which inclines in axial section with respect to the axial direction, the body portion is provided with provided a clamping element which spans the lip portion in a diameter direction of the shaft member, and an amplification section which amplifies the body portion, and the clamping element is further arranged on the side of the reinforcement section as at the tip end of the lip portion in the axial sectional shape of the lip portion.