A plasma generating method and apparatus which use plural high-frequency antennas 2 to generate inductively coupled plasma, and a plasma processing apparatus using the apparatus. The antennas 2 are identical to one another. Application of a high-frequency electric power to the antennas 2 is performed from a high-frequency power source 4 which is disposed commonly to the antennas 2, through one matching circuit 5 and one busbar 3. The busbar 3 is partitioned into sections the number of which is equal to that of the antennas, while setting a portion which is connected to the matching circuit 5, as a reference. One-end portions of the antennas are connected to corresponding sections 31, 32, 33 through power supplying lines 311, 321, 331. The other end portions of the antennas are grounded. The impedances of the sections of the busbar, and those of the power supplying lines are adjusted so that same currents flow through the antennas, and a same voltage is applied to the antennas. Therefore, the inductively coupled plasma is generated while uniformalizing high-frequency electric powers supplied to the antennas 2.