Provided is an anti-B7-H3 antibody specifically recognizing a B7-H3, which can be usefully as a cancer therapeutic agent, as having an inhibitory activity of an immune checkpoint which induces antibody-dependent cell-mediated cytotoxicity and T cell activation inhibited by B7-H3. In particular, the antibody having the inhibitory activity of an immune checkpoint can be used in combination with other immunoantibody therapeutic agents. In addition, it can be usefully used for cancer targeting treatment including detection of various cancers expressing B7-H3 through specific binding to B7-H3, and drug delivery to specific cancer, etc.