Provided is an electrode sheet allowing easy connection of a wiring that is extended, when required, to a measurement position on a living body. The electrode sheet (main sheet (1), auxiliary sheet (10)) includes a sheet-shaped flexible substrate (2, 11), wirings (3, 12) formed on the flexible substrate (2, 11), electrodes (5, 14) formed on the flexible substrate (2, 11) and electrically connected to the wirings (3, 12), and an insulating layer (4, 13) laid on the flexible substrate (2, 11) in such a manner that the wirings (3, 12) are overlaid with the insulating layer (4, 13) while the electrodes (5, 14) are exposed. The electrodes (5, 14) are formed of a conductive material in which conductive particles are dispersed in a thermoplastic resin.