A composition, which can be used in an ink jet printing method, can use either a non-polar or a weakly polar material as a functional material, prevents clogging at dispensing time, achieves stable dispensing, and prevents precipitation of content matter during dispensing and phase separation during film formation, a uniform, homogenous functional film formed using this composition and a manufacturing method therefor, as well as an organic EL device or other such display device and a manufacturing method therefor. A composition of the present invention consists of a functional material, and a solvent comprising at least one benzene derivative, which has one or more substituents, and these substituents have 3 or more carbon atoms in total. A functional film of the present invention is formed using the above-mentioned composition. A display device of the present invention comprises luminescent material layers formed using the above-mentioned composition between two electrodes. The above-mentioned display device is an organic EL device or the like.