Disclosed is a discharge device including a power source (52), a discharge electrode (61) having a plurality of discharge needles (64) each being in a linear shape or a rod-like shape, and a counter electrode (71) opposed to a tip of each of the discharge needles (64). The discharge device provides a streamer discharge from the tip of each of the discharge needles (64) toward the counter electrode (71) as a result of receiving a potential difference applied to the discharge electrode (61) and the counter electrode (71) from the power source (52). The plurality of discharge needles (64) are arranged parallel to one another.
