An antibody, or a functional fragment of an antibody, specifically binding to the amino acid sequence of the EC3 domain of cadherin-6 shown in SEQ ID NO: 4 and having internalization ability that permits cellular uptake, wherein the antibody or the functional fragment of the antibody comprises CDRL1, CDRL2 and CDRL3 in any one combination selected from the group consisting of the following combinations to: CDRL1 consisting of the amino acid sequence shown in SEQ ID NO: 12, CDRL2 consisting of the amino acid sequence shown in SEQ ID NO: 13, and CDRL3 consisting of the amino acid sequence shown in SEQ ID NO: 14, CDRL1 consisting of the amino acid sequence shown in SEQ ID NO: 22, CDRL2 consisting of the amino acid sequence shown in SEQ ID NO: 23, and CDRL3 consisting of the amino acid sequence shown in SEQ ID NO: 24, CDRL1 consisting of the amino acid sequence shown in SEQ ID NO: 32, CDRL2 consisting of the amino acid sequence shown in SEQ ID NO: 33, and CDRL3 consisting of the amino acid sequence shown in SEQ ID NO: 34, and CDRL1 consisting of the amino acid sequence shown in SEQ ID NO: 42, CDRL2 consisting of the amino acid sequence shown in SEQ ID NO: 43, and CDRL3 consisting of the amino acid sequence shown in SEQ ID NO: 44, and CDRH1, CDRH2 and CDRH3 in any one combination selected from the group consisting of the following combinations to: CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 17, CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 18, and CDRH3 consisting of the amino acid sequence shown in SEQ ID NO: 19, CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 27, CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 28, and CDRH3 consisting of the amino acid sequence shown in SEQ ID NO: 29, CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 37, CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 38, and CDRH3 consisting of the amino acid sequence shown in SEQ ID NO: 39, CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 47, CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 48, and CDRH3 consisting of the amino acid sequence shown in SEQ ID NO: 49, and CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 17, CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 60, and CDRH3 consisting of the amino acid sequence shown in SEQ ID NO: 19. CDRL1 consisting of the amino acid sequence shown in SEQ ID NO: 12, CDRL2 consisting of the amino acid sequence shown in SEQ ID NO: 13, and CDRL3 consisting of the amino acid sequence shown in SEQ ID NO: 14, CDRL1 consisting of the amino acid sequence shown in SEQ ID NO: 22, CDRL2 consisting of the amino acid sequence shown in SEQ ID NO: 23, and CDRL3 consisting of the amino acid sequence shown in SEQ ID NO: 24, CDRL1 consisting of the amino acid sequence shown in SEQ ID NO: 32, CDRL2 consisting of the amino acid sequence shown in SEQ ID NO: 33, and CDRL3 consisting of the amino acid sequence shown in SEQ ID NO: 34, and CDRL1 consisting of the amino acid sequence shown in SEQ ID NO: 42, CDRL2 consisting of the amino acid sequence shown in SEQ ID NO: 43, and CDRL3 consisting of the amino acid sequence shown in SEQ ID NO: 44, and CDRH1, CDRH2 and CDRH3 in any one combination selected from the group consisting of the following combinations to: CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 17, CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 18, and CDRH3 consisting of the amino acid sequence shown in SEQ ID NO: 19, CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 27, CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 28, and CDRH3 consisting of the amino acid sequence shown in SEQ ID NO: 29, CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 37, CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 38, and CDRH3 consisting of the amino acid sequence shown in SEQ ID NO: 39, CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 47, CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 48, and CDRH3 consisting of the amino acid sequence shown in SEQ ID NO: 49, and CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 17, CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 60, and CDRH3 consisting of the amino acid sequence shown in SEQ ID NO: 19. CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 17, CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 18, and CDRH3 consisting of the amino acid sequence shown in SEQ ID NO: 19, CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 27, CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 28, and CDRH3 consisting of the amino acid sequence shown in SEQ ID NO: 29, CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 37, CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 38, and CDRH3 consisting of the amino acid sequence shown in SEQ ID NO: 39, CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 47, CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 48, and CDRH3 consisting of the amino acid sequence shown in SEQ ID NO: 49, and CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 17, CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 60, and CDRH3 consisting of the amino acid sequence shown in SEQ ID NO: 19.