A driving device of a display medium, includes: an applying unit that applies a gray level adjusting voltage including unit pulses in accordance with a gray level of a pixel to the pixel of a display medium; and a control unit that controls the applying unit so that the number of unit pulses of the gray level adjusting voltage which is applied at a movement time of each of plural types of panicle groups is equal to the number of unit pulses of the gray level adjusting voltage which is applied at the movement time of a particle group having the highest threshold value among the plural types of particle groups.