The invention provides a ball screw lubricative sealing device having a simplified lubrication mechanism. It is attachable to an installed standard ball screw nut, capable of retaining larger amount of lubricant and long supply of lubricant to the contacting screw parts, and further includes a sealing function. It includes: generally cylindrical case members having attachment part to be attached to both ends of a screw nut, respectively; plural thin seal plates made of lubricating oil impregnated felt-like fiber material which is a three-dimensionally crosslinked plastic fiber and resilient rubber members, and having a hole each and fitted inside said case member in such a state that they circumferentially overlap with each other, the hole having a shape corresponding to a lateral cross-sectional shape of a screw groove of ball screw shaft; and a plastic wiper fitted with a space from the thin seal plates inside each of the case member.