Abstract: An ion implanter systems in which a deflector system comprises a first multiple pole electrostatic deflector having five or more poles for deflecting ion beams and a second multiple pole electrostatic deflector having poles of the same number as that of said first multiple pole electrostatic deflector and disposed coaxially at the rear of said first multiple pole electrostatic deflector for deflecting and pointing the ion beams deflected by said first multiple pole electrostaic deflector to a definitely predetermined direction, and said first and second deflectors are controlled so as to scan a region defined by an equilateral polygon whose sides are in number equal to or twice the poles of said each electrostatic deflector.