NOVELTY - An alkali metal sulfur-type secondary battery has positive electrode (2) or negative electrode(4) containing sulfur electrode active material including elemental sulfur, metal sulfide, metal polysulfide, and organosulfur compound, electrolyte containing ether compound (I), alkali metal salt, and solvent, in which at least one portion of ether compound and alkali metal salt form a complex, and counter electrode. The counter electrode contains active material which carries out occlusion desorption of the alkali metal, alloy-containing alkali metal, carbon or alkali metal ion.    USE - Alkali metal sulfur-type secondary battery e.g. lithium-sulfur secondary battery is used for mobile telephone, electric vehicle and hybrid electric vehicle.    ADVANTAGE - The alkali metal sulfur-type secondary battery has excellent durability, improved input-output density and columbic efficiency, and suppressed secondary reaction during charging. The decrease in discharge capacity due to repeated charging and discharging of the secondary battery is suppressed.    DETAILED DESCRIPTION - An alkali metal sulfur-type secondary battery has positive electrode (2) or negative electrode containing sulfur electrode active material including elemental sulfur, metal sulfide, metal polysulfide, and organosulfur compound, electrolyte containing ether compound of formula: R1-(OCHR3CH2)x-OR2 (I), alkali metal salt, and solvent, in which at least one portion of ether compound and alkali metal salt form a complex, and counter electrode. The counter electrode contains active material which carries out occlusion desorption of the alkali metal, alloy-containing alkali metal, carbon or alkali metal ion. The solvent has hydrophobicity and mixes completely with the complex. The solvent is chosen from fluorine-type solvent which is not chemically reacted with the alkali metal, and multi-alkali sulfide metal (M2Sn), ionic liquid and toluene.    R1,R2=1-9C alkyl optionally substituted with fluoro, or phenyl or cyclohexyl (both optionally substituted with halo);    R1+R2=ring;    R3=H or CH3;    x=0-10;and    n=1-8.    DESCRIPTION OF DRAWING(S) - The drawing shows the sectional view of the lithium-sulfur secondary battery.    Positive electrode (2)    Negative electrode (4)    Separator (6)    Gasket (10)    Spring (14)