A human antibody or a functional fragment thereof having specific binding ability to CD98 which is derived from the cell membrane of cancer cells and is in the form of a complex with a protein having an amino acid transporter activity (for example, LAT1) is disclosed. This antibody binds to CD98 in the form of a dimer with LAT1 on the surface of cancer cells, specifically attacks cancer cells expressing CD98 via the immune system by ADCC or CDC, and further inhibits amino acid uptake of the cancer cells via LAT1, to suppress growth of the cancer cells. Accordingly, a preventive and therapeutic agent for cancer comprising this antibody or a fragment thereof, which acts on various cancers, is specific to cancer, and causes no side effect, is provided.
