To facilitate quick attachment/detachment to/from an attachment or a grout hose and prohibit the extraction of the grout hose in an attached condition.

The grout hose 4 is mounted on the detachable fitting by inserting an interposition body 3 in a hollow storage portion of a fastener 2 and then threading the fastener 2 to a body 1 with the operation of a handle 25 and temporarily stopping the threading in the state that a female screw is threaded on its way. Herein, an opening end of the grout hose 4 is inserted into an insertion portion 16 of the body 1. The handle 25 is rotated again for further threading operation, whereupon the interposition body 3 in the hollow storage portion is compressed by thrust from a tapered end face 14a of a body portion 14 and a tapered face 22a of the fastener 2 to cause the grout hose 4 to be compressed from the outer periphery and firmly pressed against the insertion portion 16.