To efficiently and comfortably perform work, by eliminating labor for storing a socket in a tool box and taking out the socket from the tool box and labor for looking about for the socket, in a tool called a socket wrench or a ratchet wrench.

A box 4 fitted to a bolt head different in a dimension is arranged on both ends of the socket, and an installation hole 5 fitted to a socket installing part 6 is arranged between the boxes of its both ends. An extensible installation shaft 2 is arranged for lengthening the projection length of a socket installing shaft 9a on the tip of a lever 12 or extending a socket installing shaft 9. A socket holding part 13 is desirably arranged in an end part of the lever 12. The work can be performed by installing four sockets in a conventional structure on the lever 12, and fastening-loosening work of four kinds of bolts and nuts can be performed without returning the socket to the tool box and without placing the socket on a floor.