Die cutting machining methods are widely used in the packaging or printing industry, for the paperboard, labels, laminated resin sheets, ductile metal film and etc. Two industrial methods had been applied on the die cutting industry field. One is a flat plate cutting method. The other is a rotary cutting type method with the designed engraved cutter blade. This paper describes the rotary machining process of an aluminum thin sheet. FEM simulation as well as practical experimental cutting on a specially-designed, small size, machine were carried out to clarify the cutting mechanism of the rotary cutting process using cross cutter. The deformation and fracture behavior of the aluminum sheet is discussed considering the crack generation and propagation phenomena.