An exemplary neural electrode device as disclosed includes a storage in which fluid is stored an electrode array which delivers the fluid to a subject, acquires bio-signals from the subject, or provides stimulus to the subject an electronic circuit unit which allows the fluid to flow from the storage to the electrode array, processes the bio-signals acquired from the electrode array, or provides stimulus signals to the electrode array and a connection portion which includes a cable extending from the storage to the electrode array and provided with a leading wire electrically connecting the electrode array to the electronic circuit unit, and a fluidic channel through which fluid flows between the storage and the electrode array.