Provided is a novel shrimp allergen. The shrimp allergen of the present invention includes an isolated shrimp collagen or a polypeptide fragment thereof. According to the present invention, there is provided the novel shrimp allergen, and there are provided, using the allergen, an anti-shrimp allergen antibody, a method of detecting contamination of a shrimp allergen, an agent for detecting contamination of a shrimp allergen, a method of measuring sensitivity to a shrimp allergen, and an agent for measuring sensitivity to a shrimp allergen.