Vacuum leak testing apparatus of the bellows according to the present invention is to be sucked and the vacuum pump 11 and the vacuum inlet hose 12 connected to both side portions of the bellows (B) for sucking the air present in the interior of the bellows (B) inspection means 10 consisting of a gas detection unit 13 for detecting a gas in the air and; Coupled to the bellows (B) one end of a plate-like first drilling (21a) formed in the center for attachment to a horizontal first mounting plate 21 and the first drilling (21a) of the vacuum inlet hose ( No. 12) and connected to the first vacuum connection 22, the first mounting plate 21 is such that the upright is fixed the first mounting plate 21 is first mounted on the lower part connected to the horizontal made of a plate 23 one seating means 20 and; And said first mounting means (20) and is formed so as to be opposed to the second attachment plate 31, the second bores (31a) in the center of the other end of the bellows (B) to be attached to the other surface are formed, and the second connected to bores (31a) and horizontally in the lower portion of the second vacuum connection 32 connected to the vacuum inlet hose 12, the second mounting plate 31, the second mounting plate 31 so that the upstanding a second second mounting consisting of mounting plate 33 and the second mount is provided in the lower portion of the plate 33 and the second second seating moving part 34 to mount to move the plate 33 horizontally provided means (30) and; The first mounting means 20 or the second mounting means 30 of the base portion 40 on the plate to be seated thereon; consist of the effect of whether or not breakage of the bellows to expand the surface of the bellows in the horizontal accurately determine a.