There is provided a normally-off type transistor made of a nitride semiconductor. The transistor includes; an undoped GaN layer which forms a channel region; an undoped Al0.2Ga0.8N layer which is formed on the undoped GaN layer and has a band gap larger than that of the undoped GaN layer; a p-type Al0.2Ga0.8N control layer which is formed on the undoped Al0.2Ga0.8N layer, has a p-type conductivity and forms a control region; an Ni gate electrode which contacts with the p-type Al0.2Ga0.8N control layer; a Ti/Al source electrode and a Ti/Al drain electrode which are formed beside the p-type Al0.2Ga0.8N control layer; and an Ni ohmic electrode which is connected to the undoped GaN layer and serves as a hole absorbing electrode. With this transistor, it is possible to achieve a large-current operation and a high switching speed.