Provided are a substance capable of binding to EGFR specifically with a high affinity and a pharmaceutical agent containing the substance. Apeptide which contains at least an amino acid sequence represented by the formula (1), (2) or (3) and is composed of 12 to 50 amino acids: €ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒX 1 -His-X 2 -X 3 -Asp-X 4 -X 5 -X 6 -X 7 -X 8 -Trp-His€ƒ€ƒ€ƒ€ƒ€ƒ(1) (In formula (1), X 1 represents Trp or Phe X 2 represents Leu, Met, Ile or Val X 3 represents Ser, Ala, Thr, Gly, Asn, Asp, Glu, Arg or Lys X 4 represents Leu, Met, Ile, Val, Ala, Phe, Tyr, Trp, His or Cys X 5 represents Trp, Phe or Tyr X 6 represents Gln, Asn, Asp, Glu, Ala, Ser, Thr, Leu, Met, Lys or Arg X 7 represents Asn, Gln, Asp, Glu, Ser, Thr, Ala, Gly, Lys or Arg and X 8 represents Ala, Gly, Ser, Thr, Asn, Val or Cys) €ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒPhe-His-Asp-Trp-X 11 -Pro-X 12 -X 13 -X 14 -X 15 -X 16 -X 17 €ƒ€ƒ€ƒ€ƒ€ƒ(2) (In formula (2), X 11 represents Leu, Met, Ile, Val, Ala, Phe, Tyr, Trp, His or Cys X 12 represents Glu, Asp, Gln, Asn, Ala, Ser, Thr, Lys, Arg or His X 3 represents Val, Ala, Leu, Ile, Met, Thr, Cys or Asn X 14 represents Ser, Ala, Thr, Gly, Asn, Asp, Glu, Arg or Lys X 5 represents Pro, Val, Ile, Lys, Ala, Met, Trp, Tyr, Ser, Thr, Cys or Phe X 16 represents Pro, Val, Ile, Lys, Ala, Met, Trp, Tyr, Ser, Thr, Cys or Phe and X 17 represents Asp, Glu, Asn, Gln, Ala, Ser, Thr, Lys, Arg or His) and €ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒLeu-His-X 21 -Ser-X 22 -Trp-Met-X 23 -X 24 -X 25 -X 26 -X 27 €ƒ€ƒ€ƒ€ƒ€ƒ(3) (In formula (3), X 21 represents Gln, Asn, Asp, Glu, Ala, Ser, Thr, Leu, Met, Lys or Arg X 22 represents Glu, Asp, Gln, Asn, Ala, Ser, Thr, Lys, Arg or His X 23 represents Tyr, Phe, Trp, His, Leu, Met, Ile, Val, Cys or Ala X 24 represents Val, Ala, Leu, Ile, Met, Thr, Cys or Asn X 25 representsAsp, Glu, Asn, Gln, Ala, Ser, Thr, Lys, ArgorHis X 26 represents Ile, Val, Leu, Met, Ala, Phe, Tyr, Trp or Gly and X 27 represents His, Tyr, Phe, Lys, Arg, Leu, Met or Ala.)
