(Proposal ID) S11A-010 (PI) Kashikawa, Nobunari (Proposal Title) The First Direct Detection of the First Stars (Abstract) We found a very plausible Population III (PopIII) candidate SDF-popIII-1 which has an extraordinary large intrinsic rest-frame equivalent width of EW^int_0 ~ 800Angstrom in the Lyalpha emission line. The SDF-popIII-1 was spectroscopically confirmed to be a real LAE by its apparent asymmetric Lyalpha line profile detected at z = 6.545. The continuum emission of SDF-popIII-1 was actually detected in z'-band image and its EW0 was reliably determined. Such an enormous EW^int_0 ~ 800Angstrom in the Lyalpha emission cannot be attained by the Population II synthetic cluster, and only achieved in the case of PopIII with ages as young as < 2Myr. We propose deep MOIRCS spectroscopy to detect its He ii emission line at 12373.8Angstrom, which would definitely represent the first direct detection of PopIII-dominated object. This exciting discovery will exactly identify the critical epoch when the universe begins to be enriched by metals, and must have a strong impact on theoretical predictions about IMF, mass loss strength and age of PopIII. These will be discussed along with independent estimates of stellar mass, age, and dust extinction by our upcoming deep HST-NICMOS+Spitzer joint observation targeting our z = 6.5 LAE sample, which includes SDF-popIII-1.