Nowadays there are several researches about alternative and renewable energy sources. The ocean wave energy can be an option to produce electrical energy. Among the different principles to transform the wave energy into electrical the Oscillating Water Column (OWC) converter is one of the most promising. Accordingly, in this work the influence of the hydro pneumatic chamber shape in the performance of the OWC converter was analyzed. For this a computational model based on the Finite Volume Method (FVM) and using the Volume of Fluid (VOF) approach was employed. The results indicating that an improvement of 35.6% can be obtained.