Abstract: An ion source apparatus has a body, a heat dissipating base, at least two supporting shafts, a guiding block, and a shunt. The body has a holding chamber formed inside the body. The heat dissipating base is located in the holding chamber of the body. The at least two supporting shafts are mounted through the heat dissipating base. The guiding block is mounted on the at least two supporting shafts, and is a hollow circular block. The shunt is located at a center of a top surface of the heat dissipating base, and is located below the mounting hole of the guiding block.