To provide a guide tool for folding door capable of easily adjusting the protruding quantity of a shaft member while being manufacturable at a low cost with the same number of part items as that for a conventional guide tool having no adjustment mechanism.

This guide tool comprises a bottomed cylindrical socket 1 opened in the lower surface; a stopper member 2 having an axially extending insert hole 2a and mounted on the opening of the socket by being screwed to a thread 1a formed on the inside surface of the socket 1; a shaft member 3 having a major diameter head part 3a, a shaft part 3b inserted to the insert hole 2a of the stopper member 2 so as to be only vertically slidable in the state where the relative rotation is arrested, and a lower end part 3c protruded out of the insert hole 2a; and a spring 4 for regularly elastically pressing down the shaft member 3. The shaft member 3 comprises a rotating operation part 3b for fitting a rotating tool, and the rotating operation part 3b is at least partially exposed from the lower end of the socket.