To provide a method by which a cycloalkane can be oxidized in a good conversion rate to produce a cycloalkanol and/or a cycloalkanone with good selectivity.

The method for producing the cycloalkanol and/or the cycloalkanone comprises oxidizing the cycloalkane in the presence of meso-porous silica with oxygen. In the method for producing the cycloalkanol and/or the cycloalkanone, (1) the meso-porous silica contains at least one transition metal and (2) the ratio of the total volume of meso-porous silica particles having 20 m particle diameter to the total volume of the whole meso-porous silica particles is 25% in the meso-porous silica.