Cu-Zn particles have been reported to have good properties as catalysts for methanol synthesis. Particles prepared by gas evaporation methods are expected to have good properties as catalysts, because they have less impurities compared with those prepared by other methods. It is, however, difficult to produce Cu-Zn particles of uniform compositions by gas evaporation methods because of the large difference between the vapor pressures of Cu and Zn. A Zn rod is inserted to molten Cu metal instead of evaporating Cu-Zn alloy to avoid this difficulty. It has been confirmed that the Cu-Zn particles have the following complex structure ; Cu particles of several tens nanometer in diameter are covered with ZnO particles of 2 to 3 nm in diameter. These ZnO particles are grown in the slow oxidation process of Zn particles. These Cu-Zn particles show good conversion rate and selectivity as catalysts for methanol synthesis.