Abstract: A method for producing a purified peptide from a supported crude peptide having a support and a first peptide chain bonded to the support at the C-terminus. The method includes: introducing a linker and a hydrophilic unit to an amino group of the first peptide chain of the supported crude peptide; cleaving a bond between the first peptide chain and the support before or after at least one of the linker and the hydrophilic unit is introduced to the amino group of the first peptide chain such that a support-free hydrophilized peptide is obtained; treating the support-free hydrophilized peptide by liquid chromatography; and cleaving a bond between the linker and the first peptide chain in the support-free hydrophilized peptide by chemical treatment after the liquid chromatography treatment such that a peptide including the first peptide chain is obtained.