To provide a seal inspection apparatus with a grommet that can easily attach and detach the grommet with high attachment stability and conveniently and accurately perform a seal inspection.

A retaining fixation member 40 is arranged so as to freely attach and detach an air tank 30 with facing to it. An attachment hole 32 is blocked up to a sealed state with a flange 20 of the grommet 20 which is put between the air tank 30 and the retaining fixation member 40. An elastic member 25 urging in a direction separating the air tank 30 and the retaining fixation member 40 is placed between both of them. An air bubble is generated with water stored inside the retaining fixation member 40 when a seal state between the grommet 15 and a wire harness is imperfect. Pressurized air is supplied to the air tank 30 to inspect the seal state of the grommet 15.