The development of a continuous process for supercritical fluids is desirable for high-pressure technology. In a previous study, it was revealed that a twin-screw extruder was applicable as the reactor and feeder for industrial supercritical fluid processes (Goto, T.; et al. Ind. Eng. Chem. Res. 2011, 50, 5661-5666). The advantages of twin-screw extruders include their conveying ability and flexibility of design, which make them ideal for research on the applications of extruder. However, twin-screw extruders are expensive because of their complicated gearbox, cylinder shape, screw, etc. Here we report that a single-screw extruder, which is less expensive and simpler than a twin-screw extruder, is also applicable as the reactor and feeder for commercial supercritical fluid processes. Moreover, the equipment for a single-screw extruder is more compact than that of a twin-screw extruder. The results of this study will promote the application of extruders in supercritical fluid engineering research and contribute to the industrialization of a wide range of supercritical fluid techniques.