Abstract: The invention relates to an internal pressure equilibrium adjustment device for airtight space with rapid operation and simple structure. The invention comprises of a pipe 8 which is mounted on the wall 9 of airtight space and has a plurality of holes 81 at the periphery, a case 7 which surrounds the external periphery of the pipe 8 and has a plurality of holes 71 on the wall, a first port 3 which is formed at one end of the case 7, a first ring 4 which is provided above the first port 3, a second port 5 which is formed at the partition wall 12 of the case 7, and a second ring 6 which is provided above the second port 5.