An acetaldehyde, a representative food waste odor, was decomposed using a hybrid system comprised of a non-thermal plasma and catalyst at an ambient temperature under high humidity. A five wt.% Mn was impregnated on two differently structured microporous zeolites, namely Beta and ZSM-5, with a different molar ratio of SiO2/Al2O3. Under high humidity conditions, the acetaldehyde degradation was higher in zeolites with the high ratio of SiO2/Al2O3. Among studied catalysts, a five wt.% Mn/Beta (SiO2/Al2O3 = 300) showed the highest acetaldehyde removal activity owing to its high hydrophobicity and reducibility. During long term stability test using the same catalyst for 110 hours, the acetaldehyde removal activity was relatively well-maintained.