Abstract: A technique for arranging spacers with no streaks is provided. On columns of a light-shielding zone of a coating object, ejection positions are set and stored as temporary ejection positions in a memory unit. Random numbers of positive or negative real values are generated by a random number generating function. Every time a positive or negative random number is generated, one temporary ejection position and one random number are correlated to each other and stored as a random number coefficient R. Assuming that the coordinate of the temporary ejection position is expressed by (X, Y), a corrected ejection position (X+L×R, Y) is determined by multiplying the stored random number coefficient R with the interval L between the adjacent temporary ejection positions in the same column, and adding the value of the coordinate X to the multiplied value. The determined corrected ejection position is stored.