Project Profile：This project is an improvement version of current convection oven, to make it special with function of roasting sweet potato and display the cooked sweet potato in an integrated machine. We improved the structure and guide the excessive heat to top for sweet potato warming. We improved the grid, top cover, air mask etc. to combine the display and oven together. This project is good to save cost, save space and save energy. In this project, we involved technologies of new air convection, heat recycling, auto humidity, no frost door etc. The products are already in market and work well.