The present invention relates to an antibody binding to a carbonic anhydrase, wherein the antibody comprises (a) the amino acid sequences SEQ ID NOS. 1 (CDR 1 ), 2 (CDR 2) and 3 (CDR 3) determining the CDRs of the VH region, and the amino acid sequences SEQ ID NOS. 4 (CDR 1 ), 5 (CDR 2) and 6 (CDR 3) determining the CDRs of the VL region; or (b) the amino acids sequences of (a), wherein at least one amino acid is conservatively substituted in any one of the amino acid sequences SEQ ID NOS. 1 to 6.