In layer based machining (LBM), a part is sliced into thick layers, and each layer is shaped by 5-axis robot machining. Therefore, this technique is expected to have the merits of both layered manufacturing and CNC machining. As a new process, manufacturability analysis of LBM is carried out to determine whether a given part is suitable for LBM or not. This analysis is further studied based on supportability analysis and machinability analysis. Results of the manufacturability analysis are used for LBM process parameter selection and build orientation determination.