A screen-printed carbon nanotube (CNT) paste for applications to field emission emitters was treated with He, He/Ar, and He/N2 atmospheric pressure plasmas. The effect of the different plasma treatments on the field emission characteristics of the screen-printed CNTs was investigated. The atmospheric pressure plasma applied to the screen-printed CNT paste for 10 s resulted in a reduction in the turn-on electric field. In particular, the application of a He/N2 plasma treatment decreased the turn-on electric field from 3.13 to 1.29 V/μm and increased the field enhancement factor from 737 to 2775 after the treatment. These results suggest that an adequate atmospheric pressure plasma treatment of screen-printed CNTs can be effective in enhancing the field emission properties.