The present invention provides a rare cell isolation device including: a first body which is disposed above a filtration membrane and includes a first inlet for injecting a biospecimen; and a second body which is disposed under the first body and bonded to the filtration membrane, wherein the first body and the second body have a disk-shaped structure to be rotatable around their centers, and the filtration membrane is disposed to be separated from the center of the second body in a radial direction.