A new metal telluride Ba3Ag3InTe6 was synthesized by solid-state reaction. This compound adopts a new two-dimensional structure constructed by AgTe4 and InTe4 tetrahedra and Ba2+ cations. The AgTe4 tetrahedra form a puckered layer and the InTe4 tetrahedra form a zig-zag chain dangling from both edges of the layer. The material possesses a narrow band gap estimated to be around 0.48 eV by UV-vis-NIR absorption spectra. The electronic band structure reveals a direct band gap at the G point of face centered primitive Brillouin zone. Ba3Ag3InTe6 is a p-type semiconductor with high Seebeck coefficients about 325 uV/K at 400 K. The electrical conductivity of 9.4 S/cm and the thermal conductivity of 0.35 W/mK give a ZT value of 0.11 at 400 K for the undoped sample. The density of states (DOS) analysis shows that the p-type hole transport is mostly achieved through the layer consisting of AgTe4 tetrahedra.