Dehydrogenation of methanol to methyl formate was carried out using copper-exchanged clays as catalysts, Methanol was selectively dehydrogenated to methyl formate on copper-exchanged laponite and fluoro tetrasilicic mica. In contrast, copper-exchanged montmorillonite and saponite only catalyzed the dehydration to dimethyl ether, and methyl formate was not formed, due to their acidities. Copper-exchanged laponite exhibited a higher dehydrogenation activity than copper-exchanged mica. This can be understood by considering the way in which their layers aggregate. The dehydrogenation activity of copper-exchanged laponite catalyst increased with the temperature of thermal treatment. The desorption of water molecules coordinating to copper was found to be responsible for the increased activity.