Mn doped ZnO films with different doping concentration were synthesized by sol gel method using the spin coating technique. Zn1-xMnxO thin films are prepared using 2-methoxyethanol solution of zinc acetate dehydrate and manganese acetate tetrahydrate. The quantity of Mn in the sol was synthesized with undoped ZnO, 2%, 4%, 6% and 8 % of Mn doped ZnO with an annealing temperature of 500°C. The FESEM images showed many spherical shaped nanoparticles on the cross-sectional of the films. The optical properties were characterized using UV-Vis where the transmittance and band gap value were affected by certain amount of Mn concentration. These films achieve tunable band gap characteristics by means of changing the dopant concentration. It shows an initial decrease of band gap for small concentrations of Mn, followed by an increase at higher Mn doping concentrations.