An antibody that binds to a DSG3 protein for use in treating lung cancer, wherein the antibody has cytotoxic activity and is selected from the group consisting of: an antibody comprising a H chain having the amino acid sequence of SEQ ID NO: 2 as CDR1, the amino acid sequence of SEQ ID NO: 4 as CDR2, and the amino acid sequence of SEQ ID NO: 6 as CDR3 and an L chain having the amino acid sequence of SEQ ID NO: 12 as CDR1, the amino acid sequence of SEQ ID NO: 14 as CDR2, and the amino acid sequence of SEQ ID NO: 16 as CDR3; an antibody comprising the H chain of, wherein the H chain has the amino acid sequence of SEQ ID NO: 8 as CH and the L chain of, wherein the L chain has the amino acid sequence of SEQ ID NO: 18 as CL; an antibody comprising the H chain of, wherein the H chain has the amino acid sequence of SEQ ID NO: 10 as CH and the L chain of, wherein the L chain has the amino acid sequence of SEQ ID NO: 20 as CL; an antibody comprising a H chain having the amino acid sequence of SEQ ID NO: 22 as CDR1, the amino acid sequence of SEQ ID NO: 24 as CDR2, and the amino acid sequence of SEQ ID NO: 26 as CDR3 and an L chain having the amino acid sequence of SEQ ID NO: 30 as CDR1, the amino acid sequence of SEQ ID NO: 32 as CDR2, and the amino acid sequence of SEQ ID NO: 34 as CDR3; an antibody comprising the H chain of, wherein the H chain has the amino acid sequence of SEQ ID NO: 28 as CH and the L chain of has the amino acid sequence of SEQ ID NO: 36 as CL; an antibody comprising the H chain of, wherein the H chain has the amino acid sequence of SEQ ID NO: 10 as CH and the L chain of has the amino acid sequence of SEQ ID NO: 20 as CL; an antibody comprising a H chain having the amino acid sequence of SEQ ID NO: 81 as CDR1, the amino acid sequence of SEQ ID NO: 83 as CDR2, and the amino acid sequence of SEQ ID NO: 85 as CDR3 and an L chain having the amino acid sequence of SEQ ID NO: 87 as CDR1, the amino acid sequence of SEQ ID NO: 89 as CDR2, and the amino acid sequence of SEQ ID NO: 91 as CDR3; an antibody comprising the H chain of, wherein the H chain has the amino acid sequence of SEQ ID NO: 28 as CH and the L chain of has the amino acid sequence of SEQ ID NO: 36 as CL; an antibody comprising the H chain of, wherein the H chain has the amino acid sequence of SEQ ID NO: 10 as CH and the L chain of has the amino acid sequence of SEQ ID NO: 20 as CL; and an antibody that binds to the same DSG3 protein epitope as the antibody of any of to. an antibody comprising a H chain having the amino acid sequence of SEQ ID NO: 2 as CDR1, the amino acid sequence of SEQ ID NO: 4 as CDR2, and the amino acid sequence of SEQ ID NO: 6 as CDR3 and an L chain having the amino acid sequence of SEQ ID NO: 12 as CDR1, the amino acid sequence of SEQ ID NO: 14 as CDR2, and the amino acid sequence of SEQ ID NO: 16 as CDR3; an antibody comprising the H chain of, wherein the H chain has the amino acid sequence of SEQ ID NO: 8 as CH and the L chain of, wherein the L chain has the amino acid sequence of SEQ ID NO: 18 as CL; an antibody comprising the H chain of, wherein the H chain has the amino acid sequence of SEQ ID NO: 10 as CH and the L chain of, wherein the L chain has the amino acid sequence of SEQ ID NO: 20 as CL; an antibody comprising a H chain having the amino acid sequence of SEQ ID NO: 22 as CDR1, the amino acid sequence of SEQ ID NO: 24 as CDR2, and the amino acid sequence of SEQ ID NO: 26 as CDR3 and an L chain having the amino acid sequence of SEQ ID NO: 30 as CDR1, the amino acid sequence of SEQ ID NO: 32 as CDR2, and the amino acid sequence of SEQ ID NO: 34 as CDR3; an antibody comprising the H chain of, wherein the H chain has the amino acid sequence of SEQ ID NO: 28 as CH and the L chain of has the amino acid sequence of SEQ ID NO: 36 as CL; an antibody comprising the H chain of, wherein the H chain has the amino acid sequence of SEQ ID NO: 10 as CH and the L chain of has the amino acid sequence of SEQ ID NO: 20 as CL; an antibody comprising a H chain having the amino acid sequence of SEQ ID NO: 81 as CDR1, the amino acid sequence of SEQ ID NO: 83 as CDR2, and the amino acid sequence of SEQ ID NO: 85 as CDR3 and an L chain having the amino acid sequence of SEQ ID NO: 87 as CDR1, the amino acid sequence of SEQ ID NO: 89 as CDR2, and the amino acid sequence of SEQ ID NO: 91 as CDR3; an antibody comprising the H chain of, wherein the H chain has the amino acid sequence of SEQ ID NO: 28 as CH and the L chain of has the amino acid sequence of SEQ ID NO: 36 as CL; an antibody comprising the H chain of, wherein the H chain has the amino acid sequence of SEQ ID NO: 10 as CH and the L chain of has the amino acid sequence of SEQ ID NO: 20 as CL; and an antibody that binds to the same DSG3 protein epitope as the antibody of any of to.