To effectively supply lubricant into an arranged range of needle rollers on an outer periphery of a supporting shaft 4 which separately supports a planetary gear wheel 3 (a planetary rolling body).

An oil passage 15 for supplying lubricant into the arranged range of the needle rollers 5 is arranged on the supporting shaft 4. A recessed portion 16 attaining to an edge of the outer periphery by denting to an axial direction and by extending to one course of a radial direction is arranged on an end of the supporting shaft 4. An end of the oil passage 15 is opened on a bottom of the recessed portion 16. A large quantity of lubricant is easily entered from the recessed portion 16 to the oil passage 15 so that the lubricant is caught by the recessed portion 16 of each supporting shaft 4 and the lubricant once caught by an inner wall surface of the recessed portion 16 is hard to discharge.