There is provided an anti-degradation agent capable of exhibiting an excellent deterioration-inhibiting property for foods, cosmetics, etc., showing a good effect even when added in a small amount, having a high heat resistance, and being free from adverse influence due to light. There are provided (1) an anti-degradation agent comprising a water-insoluble antioxidant, a water-soluble antioxidant and an emulsifying agent； and (2) an anti-degradation agent comprising a water-soluble antioxidant, and carnosol and/or carnosic acid wherein a total content of the carnosol and the carnosic acid is not less than 4% by weight.
