An extruder includes: a supply module; a mixing module to form an electrode slurry by mixing an active material, a binder, and a conductive material from the supply module; a discharge module to discharge the electrode slurry; and a sensor to measure a characteristic value of the electrode slurry. The mixing module includes a first screw and a second screw, the first screw and the second screw including screw threads on an outer circumference thereof to rotate to engage with each other; a barrel including a first barrel and a second barrel accommodating the first screw and the second screw, respectively, and facing each other to form a hole through which the electrode slurry is transmitted; a first gap adjustment module to adjust a gap between the first barrel and the second barrel; and a control module to control the first gap adjustment module based on the measured characteristic value.