Gold nanoparticles (NPs) were deposited to a zeolite-type metal-organic framework (MOF) by a simple solid grinding method. A catalyst, Au@ZIF-8, represents the first example of an active catalyst in CO oxidation by using a MOF as a novel support for noble metal NPs. The catalytic activity for CO oxidation is improved along with increasing Au loadings, and the highest catalytic activity is obtained for 5.0 wt % Au@ZIF-8, which presents half conversion of CO at approximately 170 degrees C. Gold NPs are close to being monodisperse and have no aggregation during catalytic reaction, and the catalytic activity is reproducible.