A method for making a Schottky barrier diode includes the following steps. A first metal layer, a second metal layer and a carbon nanotube composite material are provided. The carbon nanotube composite material is applied on the first metal layer and the second metal layer to form a semiconductor layer. The carbon nanotube composite material includes an insulated polymer and a number of carbon nanotubes dispersed in the insulated polymer. The semiconductor layer is in Schottky contact with the first metal layer and in ohmic contact with the second metal layer.