The disclosed electrode for use in a fuel cell comprises a flexible carbon-fiber nonwoven fabric and a fuel-cell catalyst, such as a metal catalyst or a carbon-alloy catalyst, supported on the surfaces of the carbon fibers constituting the flexible carbon-fiber nonwoven fabric. Said flexible carbon-fiber nonwoven fabric is formed by carbonizing a nonwoven fabric obtained by electrospinning a composition containing: an electrospinnable macromolecular substance; an organic compound that is different from said macromolecular substance; and a transition metal. This structure allows the provision of an electrode, for use in a fuel cell, which uses a flexible carbon-fiber nonwoven fabric as a substrate and combines the functions of a gas-diffusion layer and an electrocatalyst layer.