PROBLEM TO BE SOLVED: To provide a transgenic silkworm which can produce a non-natural amino acid-containing protein easily and a producing method of the non-natural amino acid-containing protein using the transgenic silkworm.SOLUTION: A transgenic silkworm has DNA coding a protein having activity to attach desired non-natural amino acid to phenylalanine-specific tRNA, and a promoter expressing the DNA specifically to a silk gland.