A control method of a plasma processing apparatus including a first electrode and a second electrode includes supplying a bias power to the first electrode, and supplying a negative DC voltage to the second electrode. The negative DC voltage periodically repeats a first state that takes a first voltage value and a second state that takes a second voltage value having an absolute value smaller than the first voltage value. The control method further includes a first control process of applying the first state of the negative DC voltage in a partial time period within each cycle of a signal synchronized with a cycle of a radio frequency of the bias power, or in a partial time period within each cycle of a periodically varying parameter measured in a transmission path of the bias power, and applying the second state continuously with the first state.