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Description: The present invention relates to dye-sensitized solar cells. More particularly, it relates to a dye-sensitized solar cell comprising a molten salt as its charge transfer layer (electrolyte).PRIOR ART Recent solar cells are sealed cell structures and, among these, the dye-sensitized solar cell equipped with a semiconductor layer (photosensitive layer) which comprises a photosensitive substance such as titanium dioxide carrying aphotosensitizing dye as adsorbed thereon is attracting attention because of its high photo-electric energy conversion efficiency. The dye-sensitized solar cell, for example of the construction illustrated in FIG. 7, comprises a conductive support, suchas Fluorine-doped Tin Oxide(FTO), a photosensitive layer (a semiconductor layer containing a photosensitive substance) which contains a finely divided semiconductor such as TiO.sub.2 particles sensitized by a dye such as ruthenium-2,2-bipyridine(Ru-bpy), a charge transfer layer comprising an electrolysis solvent, such as acetonitrile, and an electrolyte, such as iodine, a counter electrode made of a metal such as platinum (Pt), and a sealant sealing the electrolyte solution. The operatingprinciple of this structure is that sunlight incident from the conductive support side or the counter electrode side causes the semiconductor layer containing a photosensitive substance to release electrons under the influence of the photosensitizing dyeand the redox pair I.sup.-/I.sub.3.sup.-in the charge transfer layer acts on the counter electrode to output electric energies. Such solar cells use an organic solvent as the electrolysis solvent and, partly because of the drawback that the ready volatility and flash point of the solvent call for hermetic sealing and partly because of the high incidence of leakageleading to lack of long-term reliability and deficiencies in safety, there has been a standing demand for a constituent material with which such drawbacks could be overcome. Under the circumstances th