PURPOSE: To highly reproducibly and correctly quantify specific components in liquid sample by simple operation by constituting a recess on an absorbing body where an antibody (or antigen) has been fixed.

CONSTITUTION: Liquid sample is added to a water absorbing body A where an antibody has been fixed, and immunological reaction of the fixed antibody and an enzyme marking antibody with an antigen in the liquid sample is made occur on the water absorbing body A. Then the water absorbing water A is brought into contact with an element C to be analyzed, and the free enzyme marking antibody is transferred to the element C. Then the water absorbing body A is separated from the element C as needed, and a marked enzyme is measured to analyze the antigen in the liquid sample. A recess such as a hollow hole 1 or a recess is formed on the water absorbing body A, wherein a side with the recess formed is overlaid on the element C. Thus no damage occurs to the element C at a portion corresponding to the recess of the water absorbing body A, wherein using this portion as a light measuring part can improve simultaneous reproducibility.