In this paper, an atmospheric pressure air plasma jet with a simple dielectric barrier configuration was presented. The air plasma jet was sustained by a low-frequency (20 kHz-70 kHz) alternating-current power supply. With the compressed air driven through the discharge channel, a plasma jet of about 5 mm long was generated. The optical emission spectrum analysis indicates that chemically reactive species such as atomic oxygen, N-2 excited species, and ozone exist in the air plasma jet. (C) 2011 Elsevier B. V. All rights reserved.