According to one embodiment of the present invention, a plasma treatment apparatus comprises: a chamber having an inner space in which processes for an object to be treated are performed; and an antenna which is arranged to cover the side part of the chamber, and which forms electric fields in said inner space to generate plasma from the source gas supplied in the inner space. The antenna includes a helical antenna which is formed into a helical shape from one side of the chamber toward the other side of the chamber along a first rotation direction, and which has a current flowing in the first rotation direction; an extension antenna which is connected to one end of the helical antenna positioned at said one side of the chamber, and which has a current flowing in the direction opposite to the first rotation direction; and a connection antenna for interconnecting the extension antenna and the helical antenna.