A Ni-based single crystal superalloy which has the following composition: Co: 0.0 wt % or more to 15.0 wt % or less, Cr: 4.1 to 8.0 wt %, Mo: 2.1 to 4.5 wt %, W: 0.0 to 3.9 wt %, Ta: 4.0 to 10.0 wt %, Al: 4.5 to 6.5 wt %, Ti: 0.0 to 1.0 wt %, Hf: 0.00 to 0.5 wt %, Nb: 0.0 to 3.0 wt %, Re: 8.1 to 9.9 wt % and Ru: 0.5 to 6.5 wt % with the remainder including Ni and unavoidable impurities. As a result, the Ni-based single crystal superalloy which includes more than 8 wt % of Re in the composition ratio and has excellent specific creep strength and the turbine blade incorporating the Ni-based single crystal superalloy may be made.