To provide a connecting tool capable of allowing a worker to easily perform the connecting work alone and improving the workability in the connecting work of a main body flange and a component flange in mounting a component on a vacuum device main body.

In connecting two flanges respectively having a plurality of through holes along the circumferential direction by using this connecting tool composed of an auxiliary member having through holes corresponding to the through holes formed on the flanges, a plurality of bolts and a plurality of nuts, the plurality of bolts are inserted into the through holes of the flanges in a state that the bolts are inserted into the through holes formed on the auxiliary member, and the nuts are screwed on tips of the bolts to connect two flanges.