Abstract: In a propeller shaft apparatus in which a propeller shaft is supported by a support mechanism via a bearing, and the bearing is sealed from an external environment by a dust seal attached to an inner periphery of the support mechanism and coming into sliding contact with an outer periphery of the propeller shaft, the dust seal includes at least first and second lips extending to both sides in an axial direction, an inner diameter of a leading end of one lip of the first and second lips is made smaller than an inner diameter of a leading end of the other lip, and a cross sectional area of the one lip is made larger than a cross sectional area of the other lip.