To provide a structure for moving a wrench cylinder into and out of a socket wrench which enables the wrench cylinder to be changed with another with a differently sized wrench hole and which can be used while the projected length of the wrench cylinder is adjusted to three stages.

A mounting hole 2 is provided in at least one end of a handle main body, a wrench cylinder 3 having a wrench hole formed therein is freely slidably fitted into the mounting hole 2 so that the wrench cylinder 3 freely slides into and out of the mounting hole 2, and a stopper mechanism 4 by which the wrench cylinder 3 sliding in and out is held in a predetermined position is provided for the mounting hole 2 and the wrench cylinder 3. The stopper mechanism 4 is designed so that the wrench cylinder 3 is freely inserted into and drawn out of the mounting hole 2, and that with respect to the mounting hole 2, the wrench cylinder 3 is held at least in the position of the middle of the wrench cylinder 3 and in a position near each end of the cylinder.