A gas sensing element (1; 1b; 1c) comprising a multilayered body including: a first solid electrolytic substrate (11; 62) comprising a through-hole (110; 620) for introducing a measured gas; a porous diffusion layer covering an outer opening of said through-hole (110; 620); a second solid electrolytic substrate (13; 64); a first spacer (12; 63) provided between said first and second solid electrolytic substrates (11, 13) and defining a first measured gas chamber (121; 631) for storing the measured gas introduced through said through-hole (110; 620), and a second measured gas chamber (122; 632) communicating with said first measured gas chamber (121; 631) via a diffusion passage (120; 630); a ceramic heater; a second spacer (14; 65) provided between said second solid electrolytic substrate (13; 64) and said ceramic heater and defining a first air chamber (140; 650); a third spacer (16; 61) provided next to said porous diffusion layer and defining a second air chamber (160; 610); a pump cell constituted by first and second pump electrodes (21, 22) and said second solid electrolytic substrate (13; 64) having surfaces on which said first and second pump electrodes (21, 22) are provided, said first pump electrode positioned in said first measured gas chamber (121; 631) and said second pump electrode positioned in said first air chamber (140; 650); a pump circuit including a power source and an ammeter and connected between said first and second pump electrodes (21, 22); a sensor cell constituted by a measured gas side electrode, a reference electrode, and said first solid electrolytic substrate (11; 62) having surfaces on which said measured gas side electrode and said reference electrode are formed, said measured gas side electrode positioned in said second measured gas chamber (122; 632) and said reference electrode positioned in said second air chamber (160; 610); and a sensor circuit including a power source and an ammeter and connected between said measured gas side electrode and said reference electrode, wherein said first pump electrode of said pump cell contains Au as an additive, and said measured gas side electrode of said sensor cell is made of Pt and Rh as main components and contains Au as an additive by an amount of 0.01wt% to 0.2wt% when an overall amount of said measured gas side electrode of said sensor cell is 100wt%. a first solid electrolytic substrate (11; 62) comprising a through-hole (110; 620) for introducing a measured gas; a porous diffusion layer covering an outer opening of said through-hole (110; 620); a second solid electrolytic substrate (13; 64); a first spacer (12; 63) provided between said first and second solid electrolytic substrates (11, 13) and defining a first measured gas chamber (121; 631) for storing the measured gas introduced through said through-hole (110; 620), and a second measured gas chamber (122; 632) communicating with said first measured gas chamber (121; 631) via a diffusion passage (120; 630); a ceramic heater; a second spacer (14; 65) provided between said second solid electrolytic substrate (13; 64) and said ceramic heater and defining a first air chamber (140; 650); a third spacer (16; 61) provided next to said porous diffusion layer and defining a second air chamber (160; 610); a pump cell constituted by first and second pump electrodes (21, 22) and said second solid electrolytic substrate (13; 64) having surfaces on which said first and second pump electrodes (21, 22) are provided, said first pump electrode positioned in said first measured gas chamber (121; 631) and said second pump electrode positioned in said first air chamber (140; 650); a pump circuit including a power source and an ammeter and connected between said first and second pump electrodes (21, 22); a sensor cell constituted by a measured gas side electrode, a reference electrode, and said first solid electrolytic substrate (11; 62) having surfaces on which said measured gas side electrode and said reference electrode are formed, said measured gas side electrode positioned in said second measured gas chamber (122; 632) and said reference electrode positioned in said second air chamber (160; 610); and a sensor circuit including a power source and an ammeter and connected between said measured gas side electrode and said reference electrode, wherein said first pump electrode of said pump cell contains Au as an additive, and said measured gas side electrode of said sensor cell is made of Pt and Rh as main components and contains Au as an additive by an amount of 0.01wt% to 0.2wt% when an overall amount of said measured gas side electrode of said sensor cell is 100wt%.