Numerous nanobiodevices have been developed for cancer diagnosis through the analysis of cancer cells and cancer-related biomolecules, cancer gene therapy, and iPS cell-based regenerative medicine. A microchamber array, which is fabricated on a plastic chip, enables to develop a reliable circulating tumor cell (CTC) detection technique for cancer metastasis diagnosis. A nanopillar-array or a nanowire-array on a quartz chip allows ultrafast analysis of DNA and microRNA within 1 s for the molecular diagnosis of cancer. Immunopillar devices, which contain a tremendous amount of antibody-immobilized microparticles inside an immunopillar structure, have realized fast and low invasive “from blood to analysis” type biomarker detection of cancer with a pM detection sensitivity within 5 min. Quantum dots and gene delivery nanodevices are applied to single cancer cell diagnosis, <i>in vivo</i> imaging for iPS cell based regenerative medicine, and theranostic devices for cancer diagnosis and therapy.