Abstract: The research and development of a reflection scanning acoustic microscope operating at 500 MHz is described.The design and construction of the microscope,the acoustic transducer-focusing system,the mechanical component,the microwave and electronic system are presented.The resolution of the acoustic lens and practical ability of SAM are discussed.Experimental results show that resolution of the microscope is not worse than 2 μm.Finally,images and V(Z) curves of some specimens obtained by using the SAM are given.It exhibits some specific performance.