Abstract: Provided is a plasma treatment apparatus capable of uniform substrate treatment by correction of unevenness in a plasma density distribution. The apparatus has a configuration such that a substrate is treated with plasma, and an evacuated container is provided with an annular antenna arranged around an outer periphery of the container, and is formed of a power supply container, and a process container where the substrate is placed, which communicates with an internal space of the power supply container. The plasma is generated in the power supply container by radio-frequency power supplied to the antenna. The plasma is diffused into the process container by a magnetic field of solenoid coils arranged around an outer periphery of the antenna. The inclination of the magnetic field is adjusted by an inclination adjustment means for adjusting the inclination of the solenoid coils with respect to the process substrate.