This paper develops a novel and simple process device based on an atmospheric pressure air microplasma jet for the selective etching of parylene-C film. In order to realize the selective etching, a quartz glass microtube (100 µm, inner diameter) is employed to generate the air microplasma jet. Experimental results demonstrated Micro-holes, micro-trenches on parylene-C film were successfully fabricated by the air microplasma jet without causing any heat damage to films and using any masks, and the etching rate reached 5.14µm/min. Due to its operating at ambient conditions, this process device can be easily integrated with roll-to-roll systems for large-scale manufacturing of flexible electronic devices in the future.