A discharge device according to the present disclosure includes a discharge electrode and a voltage applicator that applies a voltage to the discharge electrode and thus causes discharge that is further developed from corona discharge at the discharge electrode. The discharge is discharge in which a discharge path is intermittently formed by dielectric breakdown so as to stretch from the discharge electrode to a surrounding. This discharge can be called leader discharge. This makes it possible to increase an amount of generated active component while keeping an increase of ozone small.