We present the properties of Ly{alpha} emitters (LAEs) at z=5.7 in the Subaru Deep Field. A photometric sample of 89 LAE candidates was constructed from narrow-band data down to NB816=26.0 (AB) in a continuous 725arcmin^2^ area. Spectra of 39 objects satisfying the photometric selection criteria for LAEs were obtained with Subaru and Keck II Telescopes, among which 28 were confirmed LAEs, one was a nearby galaxy, and eight were unclassified. We also obtained spectra of another 24 NB816-excess objects in the field, identifying six additional LAEs.