A method of manufacturing an outer joint member of a constant velocity universal joint, which is constructed by forming, through use of separate members, a cup section having track grooves formed at an inner periphery of the cup section and engageable with torque transmitting elements (19,41), and a shaft section formed at a bottom portion (12a2) of the cup section, and by welding a cup member forming the cup section and a shaft member forming the shaft section, the method being characterised by the following steps: forming the cup member and the shaft member using medium carbon steel; preparing, as the cup member, a cup member having a cylindrical portion (12a1) and a bottom portion (12a2) integrally formed, and a joining end surface formed on an outer surface of the bottom portion (12a2) in a machining step; preparing, as the shaft member, a shaft member having a joining end surface to be joined to the bottom portion (12a2) of the cup member, which is formed in the machining step, and a bearing mounting surface, which is formed at an outer periphery of the shaft member; bringing the joining end surface of the cup member and the joining end surface of the shaft member into abutment against each other; and welding the cup member and the shaft member by radiating a beam from an outer side of the cup member to an abutment portion between the cup member and the shaft member in a radial direction of the cup member under a state in which a hollow cavity portion is formed inside the abutment portion, wherein the joining end surface of the shaft member is located at the cup member side with respect to the bearing mounting surface, and one of the joining end surface of the cup member and the joining end surface of the shaft member having, on a radially inner side thereof, an annular groove portion (50a, 51a) shielded from the hollow cavity portion. the method being characterised by the following steps: forming the cup member and the shaft member using medium carbon steel; preparing, as the cup member, a cup member having a cylindrical portion (12a1) and a bottom portion (12a2) integrally formed, and a joining end surface formed on an outer surface of the bottom portion (12a2) in a machining step; preparing, as the shaft member, a shaft member having a joining end surface to be joined to the bottom portion (12a2) of the cup member, which is formed in the machining step, and a bearing mounting surface, which is formed at an outer periphery of the shaft member; bringing the joining end surface of the cup member and the joining end surface of the shaft member into abutment against each other; and welding the cup member and the shaft member by radiating a beam from an outer side of the cup member to an abutment portion between the cup member and the shaft member in a radial direction of the cup member under a state in which a hollow cavity portion is formed inside the abutment portion, wherein the joining end surface of the shaft member is located at the cup member side with respect to the bearing mounting surface, and forming the cup member and the shaft member using medium carbon steel; preparing, as the cup member, a cup member having a cylindrical portion (12a1) and a bottom portion (12a2) integrally formed, and a joining end surface formed on an outer surface of the bottom portion (12a2) in a machining step; preparing, as the shaft member, a shaft member having a joining end surface to be joined to the bottom portion (12a2) of the cup member, which is formed in the machining step, and a bearing mounting surface, which is formed at an outer periphery of the shaft member; bringing the joining end surface of the cup member and the joining end surface of the shaft member into abutment against each other; and welding the cup member and the shaft member by radiating a beam from an outer side of the cup member to an abutment portion between the cup member and the shaft member in a radial direction of the cup member under a state in which a hollow cavity portion is formed inside the abutment portion, wherein the joining end surface of the shaft member is located at the cup member side with respect to the bearing mounting surface, and one of the joining end surface of the cup member and the joining end surface of the shaft member having, on a radially inner side thereof, an annular groove portion (50a, 51a) shielded from the hollow cavity portion.