According to the present invention, an immunoisolation membrane including a porous membrane is provided at least at a part of a boundary between the inside and the outside, the porous membrane contains a polymer, and a layered dense portion having a minimum pore size is provided in the membrane. And the pore diameter continuously increases in the thickness direction from the dense portion toward both the one surface A and the other surface B of the porous film, and the porosity near the surface A is 65%. Above, the average pore size of the surface A is larger than the average pore size of the surface B, and the surface B has a transplant chamber disposed on the inner side thereof, and a biological composition is included in the transplant chamber. An implantable device is provided. The transplantation chamber of the present invention induces angiogenesis in a recipient and is unlikely to cause a decrease in substance permeability.本発明により、内部と外部との境界の少なくとも一部に多孔質膜を含む免疫隔離膜を有し、上記多孔質膜がポリマーを含み、かつ孔径が最小となる層状の緻密部位を膜内に有し、上記緻密部位から上記多孔質膜の一方の表面Ａおよび他方の表面Ｂの双方に向かって厚み方向で孔径が連続的に増加しており、上記表面Ａ付近の空孔率は６５％以上であり、上記表面Ａの平均孔径は上記表面Ｂの平均孔径より大きく、上記表面Ｂは上記内部側に配置されている移植用チャンバー、ならびに上記移植用チャンバーに生物学的構成物が内包されている移植用デバイスが提供される。本発明の移植用チャンバーはレシピエント中での血管新生を誘導するとともに物質透過性の低下が生じにくい。
