A unique hydrophobic pore is generated by the self-assembly of Leu-Leu-Leu-NH2 (1) in the crystal structure, in which the C-terminal amide groups induce the cylindrical arrangement of Leu side chains by intermolecular NH center dot center dot center dot O hydrogen bonds. This body-centered cubic-type pore provides a structural basis for devising the material to selectively extract low-molecular hydrophobic molecule such as methane.