In an effort to improve the contacting performance of a sieve tray, a meshed chamber was placed on the sieve tray. Its hydraulic and mass transfer characteristics were measured and compared with those of the sieve tray without the methed chamber. The hydraulic characteristics of a sieve tray with a meshed chamber such as dry pres-sure drops, total pressure drops, and clear liquid heads on the tray were compared with the sieve tray alone using the air-water system. Effective interfacial areas on the tray were determined from CO₂ absorption experiments in K₂CO₃-KHCO₃ buffer solution and compared with the tray with a meshed chamber.