A viscosity measuring system is equipped with a tank, a flow pathway, an external force applying unit, and a pump. The viscosity measuring system further comprises a first pressure detection unit which detects a pressure of the electrode ink, and a second pressure detection unit which detects the pressure of the electrode ink on a more downstream side than the first pressure detection unit. A detection processing unit calculates a viscosity of the electrode ink based on the pressure detected by the first pressure detection unit and the pressure detected by the second pressure detection unit.