An electrostatic deflector that can be manufactured easily and very accurately without using a member for positioning is provided. After multiple slits 81d to 88d have been formed in the same direction as that of the bus bar of an approximately conical electrode material 100 whose large-diameter section is formed with flange portions 81a to 88a for installation on an insulator 90, each of the flange portions is coupled with the insulator 90, then the electrode material 100 is cut along extension lines of the slits 81d to 88d, and thus, multiple electrode members electrically isolated from one another are formed.