The electronic, optical and thermoelectric properties of bulk and surface of CuInTe2 were investigated by first-principles calculation based on full potential linearized augmented plane wave (FP-LAPW) method. The electron-exchange correlation is taken as generalized gradient approximation (GGA). To improve the energy band gap a modified version of semi-local orbital independent potential called modified Becke Johnson (mBJ) potential is used. The calculated energy band gap of CuInTe2 is in good agreement with available experimental and theoretical results. Both the bulk and surface of CuInTe2 is a direct band gap semiconductor, shows a transition along (Γ−Γ) symmetry point. The calculated band gap of surface and bulk within GGA/mBJ are 0.38/0.63 eV and 0.75/1.13 eV, respectively. This shows an optical interaction of materials at UV range, which can exploited as a heterojunction absorptive layer for solar cell materials. The thermoelectric properties were also calculated based on the Boltzmann semi-local transport theory. The flat and sharp bands along (Γ−Γ) in bulk and surface is responsible for high value of Seebeck coefficient and electrical conductivity, respectively. The higher value of Seebeck coefficient and electrical conductivity is a key to enhance the thermoelectric efficiency.