To improve the precision of separation by arranging four adjacent opposite tubes at the corners of a parallelogram having no right angles respectively in a tubular electrostatic separator which is composed of two parallel opposite rows of vertical tubes and connected with a direct current voltage source in order to maintain an electrostatic field.

A tubular electrostatic separator suitable for separating a plastic mixture, especially a plastic mixture which has similar density and is incapable of ordinal floating separation is composed of two parallel rows of vertical tubes, and each tube is installed rotatably around each axis or fixedly. A direct current voltage source is connected to each tube in order to maintain an electrostatic field. The tubes are installed so that the interval between them is 1.5 times the diameter of the individual tubes, and the adjacent tubes are arranged respectively alternately, namely in such a manner that the centers of two adjacent tubes of one electrode form an isosceles triangle together with respective one center of the tube of the other electrode.