A method of manufacturing an image forming apparatus is provided for increasing the uniformity of an electron-emitting device, improving the electron-emitting characteristics, and permitting the manufacture of an image forming apparatus having an excellent display quality to be retained for a long time. The image forming apparatus is manufactured by forming a plurality of pairs of electrodes (2, 3) on a first substrate (1), forming a polymer film containing a photosensitive material such that the polymer film makes a connection between the electrodes (2, 3), patterning the polymer film into a desired configuration by the irradiation of light, lowering the resistance of the patterned polymer film to form a conductive film (6), and forming a gap (5) in a part of the conductive film (6) by the flow of a current between the electrodes (2, 3). Subsequently, the first substrate 1 and the second substrate on which an image forming member is disposed are connected through a joining member under a reduced pressure atmosphere to construct an image forming apparatus.