This paper concerns the stability improvement and noise reduction of an axial compressor caused by the foam metal casing treatment (FMCT). Three FMCTs with different PPI (pores per inch), 20, 35, and 50, are tested experimentally. Two installation locations of foam metal in casing are considered and investigated. At location 1, it is found that the FMCT improves the stall margin by 5.4%~8.7% and the attenuation of compressor noise is up to 5 dB. At location 2, the stall margin is extended by 22.2%~37.1% but increasing the noise mostly. Besides, foam metal at location 1 causes less efficiency loss than that in location 2. Based on the analysis in near-casing pressure distribution, spanwise performance comparison and stall inception, the mechanism of the FMCT for enhancing compressor stability is also discussed.