Provided is a method for producing a peptide containing an N-alkylamino acid, comprising the following steps (1) to (3). Step (1): a step of mixing an N-terminal protected amino acid or an N-terminal protected peptide with a carboxylic acidhalide or an alkyl haloformate; Step (2): a step of mixing an amino acid or a peptide that is not protected at the N- and C-termini with a trialkylsilylating agent; and a step of mixing the product obtained in Step (1) with the product obtained in Step (2).