PROBLEM TO BE SOLVED: To provide a novel macrocyclic molecule, particularly to provide a macrocyclic molecule that can be bound to protein, particularly to provide a macrocyclic molecule that can be bound to Hsp90, and to provide a library and screening method which enable identification/isolation of a macrocyclic molecule that can be bound to a target molecule.SOLUTION: There are provided a library of T7 phage in which a presented peptide is modified by a crown ether derivative, and a method for screening a binding molecule to a target molecule by using the library. An Hsp90 binding molecule obtained by the screening has a structure that a peptide in which hydrophobic amino acid is arranged is bound to the crown ether derivative.SELECTED DRAWING: None
