A microwave control method is used in a microwave plasma processing apparatus including a microwave generation unit, a waveguide for guiding a microwave generated by the microwave generation unit, a tuner for controlling a position of a movable short-circuiting plate, and a stub provided between the tuner and an antenna in the waveguide and insertable into an inner space of the waveguide. The method includes detecting the position of the movable short-circuiting plate controlled by the tuner for the microwave outputted by the microwave generation unit, determining whether or not a difference between a reference position and the detected position of the movable short-circuiting plate is within a tolerable range, and controlling an insertion length of the stub into the inner space of the waveguide when it is determined that the difference between the position of the movable short-circuiting plate and the reference position is not within the tolerable range.