In Japan, standardization of allergens for therapeutics and diagnosis is very limited. Only one allergen (Cryptomeria japonica) extract was standardized. The standardization of two kinds of allergens for therapeutics (Cedar pollen and Dermatophagoides allergens) is now progressing. As for food allergens, the Japanese Ministry of Health Labour and Welfare (MHLW) made a decision for mandatory labeling of foods containing allergenic ingredients in 2001. Egg, milk, wheat, buckwheat and peanut, and most recently shrimp and crab require mandatory labeling. Standardization of food allergens for allergenic ingredient measurement has been advanced.