A gas diffusion electrode (10) is formed of a woven or nonwoven textile, and is provided with a water repellent layer (1) having water repellency, and an adhesion layer (2) laminated on one surface of the water repellent layer. The gas diffusion electrode is additionally provided with a gas diffusion layer (3) that is laminated on the surface of the adhesion layer on the opposite side from the surface facing the water repellent layer. The adhesion layer is non-biodegradable, and is alkali-resistant. A microbial fuel cell (100) is provided with a negative electrode (20) for supporting microbes, an ion-permeable membrane (30) that is permeable with respect to hydrogen ions, and a positive electrode (40) comprising the gas diffusion electrode, the positive electrode (40) being separated from the negative electrode by the ion-permeable membrane.