A method for manufacturing a Schottky barrier diode includes the following steps. First, a GaN substrate is prepared. A GaN layer is formed on the GaN substrate. A Schottky electrode including a first layer made of Ni or Ni alloy and in contact with the GaN layer is formed. The step of forming the Schottky electrode includes a step of forming a metal layer to serve as the Schottky electrode and a step of heat treating the metal layer. A region of the GaN layer in contact with the Schottky electrode has a dislocation density of 1×108 cm−2 or less.