Electrode sensor for electrical impedance tomography comprising (a) an array of spaced apart individual contact elements (3, 15, 27, 27', 41), and (b) an interface structure (1, 9, 19, 19', 30, 35, 43) for forming contact between said contact elements and the skin; said interface structure (1, 9, 19, 19', 30, 35, 43) comprising - an interface layer of an essentially electrically insulating or poorly electrically conducting material (2, 10, 20, 20', 29, 37) defining a skin contact surface (7, 13, 24) on one side and an array contact surface (6, 12, 23) on the other side of the interface layer, - a first pattern of an electrically conducting material on the array contact surface (6, 12, 23), - a second pattern of an electrically conducting material on the skin contact surface (7,13, 24), and - electrical pathways (4, 14, 21, 21', 39) connecting the first pattern with the second pattern; characterized in that - the electrical pathways are mutually electrically isolated, - the first pattern comprises pattern elements, which pattern elements are mutually electrically isolated, - the second pattern comprises pattern elements, which pattern elements are mutually electrically isolated, - each individual contact element (3, 15, 27, 27', 41) comprises a contacting surface area large enough to cover several pattern elements of said first pattern when contacting the array contact surface of the interface structure, and - the electrode sensor being arranged so that by contacting distinct sections of the first pattern with said individual contact elements (3, 15, 27, 27', 41), groups of electrical pathways (4, 14, 21, 21', 39) establish contact further with distinct sections of the second pattern, so that an individual contact element (3, 15, 27, 27', 41) defines an individual effective electrode on the skin contact surface (7, 13, 24). (a) an array of spaced apart individual contact elements (3, 15, 27, 27', 41), and (b) an interface structure (1, 9, 19, 19', 30, 35, 43) for forming contact between said contact elements and the skin; - an interface layer of an essentially electrically insulating or poorly electrically conducting material (2, 10, 20, 20', 29, 37) defining a skin contact surface (7, 13, 24) on one side and an array contact surface (6, 12, 23) on the other side of the interface layer, - a first pattern of an electrically conducting material on the array contact surface (6, 12, 23), - a second pattern of an electrically conducting material on the skin contact surface (7,13, 24), and - electrical pathways (4, 14, 21, 21', 39) connecting the first pattern with the second pattern; - the electrical pathways are mutually electrically isolated, - the first pattern comprises pattern elements, which pattern elements are mutually electrically isolated, - the second pattern comprises pattern elements, which pattern elements are mutually electrically isolated, - each individual contact element (3, 15, 27, 27', 41) comprises a contacting surface area large enough to cover several pattern elements of said first pattern when contacting the array contact surface of the interface structure, and - the electrode sensor being arranged so that by contacting distinct sections of the first pattern with said individual contact elements (3, 15, 27, 27', 41), groups of electrical pathways (4, 14, 21, 21', 39) establish contact further with distinct sections of the second pattern, so that an individual contact element (3, 15, 27, 27', 41) defines an individual effective electrode on the skin contact surface (7, 13, 24).