To provide a cushion for correcting the pelvis, having a function for fastening the pelvis, and holding an lumbosacral angle to be the right angle in a seated state.

The cushion is obtained by externally mounting texture on an inner material, having a support part for holding the lumbosacral angle 8 of the sacrum 7 at the back side of a seat surface in a pelvis placement part composed of an elastic body formed in a recessed shape. By the configuration, the pelvis 5 is fastened, while holding the lumbosacral angle 8 to be the right angle in the seated state, thereby correcting the distortion and looseness of the pelvis 5.