In order to detect acoustic emission (AE) signals which are transient elastic waves generated by rapid release of strain energy derived from deformation in materials etc., general AE sensors were fabricated by using a piezoelectric film for detection of AE signals. However, these sensors required frequency domain analysis after recording AE signal. Therefore, this research has been developing an AE sensor integrated with cantilever array with different resonant frequencies for detection of AE signals divided into frequency domain by using MEMS techniques. In this paper, a design of cantilever structures was executed. Theoretical analysis and simulation using ANSYS software revealed that a resonant frequency of a cantilever was increased with decrease of its length in the range from 100 k to 1 MHz. Therefore, fabrication and frequency characterization of a cantilever array fabricated in our batch fabrication process were executed.