There is provided a plasma formation region control apparatus, with which a large-scale plasma can be obtained under a high pressure with ease and at low cost. The plasma formation region control apparatus comprises a microwave oscillator, an antenna connected to the microwave oscillator, and controller for controlling the position of each of the microwave oscillator and the antenna. The controller positions the antenna towards a plasma formation region in accordance with a specification for a plasma region for respective points in time t; establishes a driving sequence for the microwave oscillator based on the temperature state of the specified plasma; and drives the microwave oscillator according to the driving sequence.