Recently, convection heat transfer has been implemented to commercial ovens to enhance heat and mass transfer. In addition to that, conduction and radiation are also closely bound to cooking performance of an oven. Nonetheless, many unknowns regarding cooking performance are yet present due to the lack of clear understanding on heat transfer mechanisms during oven cooking. In this study, particle image velocimetry(PIV) was employed to investigate the flow field, of an oven, in which convection plays a dominant role in heat and mass transfer. Various aspects of flow (stream wise an d cross - stream wise) were studied and compared to CFD results for further analysis, which will lay a groundwork on optimal design of a commercial oven.