GAS DIFFUSION ELECTRODE AND FUEL CELL

The purpose of the present invention is to provide a gas diffusion electrode having excellent dry-up resistance and flooding resistance, the gas diffusion electrode also having excellent power generation performance across a wide temperature range. In order to achieve this purpose, the present invention is configured as described below. Specifically, the present invention is a gas diffusion electrode having a microporous layer on at least one surface of an electroconductive porous substrate, wherein: the microporous layer has a first microporous layer in contact with the electroconductive porous substrate, and a dense layer in contact with the first microporous layer; the thickness of the dense layer is at least 1 µm; and the average number density B of pores having a pore diameter of 0.15-1 µm in the dense layer is at least 1.3A, where A is the average number density of pores having a pore diameter of 0.15-1 µm in the microporous layer disposed on at least one surface of the electroconductive porous substrate,.