PURPOSE: To enable to perform a rapid analysis of a fluid sample containing a specified component irrespective of a molecular weight and whether it is water solubility or hydrophobic nature, by a method wherein one layer of reagent layers in an analyzing element for analyzing a specified component previously determined in fluid consists of a nucleus comprising an inorganic material having a hydrophobic nature an being non-swelling to a fluid sample and polymer particle unit having a nuclear shell multilayer construction comprising an outer shell.

CONSTITUTION: One layer of reagent layers in an analyzing element consists of a nucleus having a hydrophobic nature and being non-swelling to a fluid sample and a polymer particle unit of a nuclear shell two-layer construction having a hydrophilic shell surrounding the nucleus. An inorganic material forming a nucleus part is preferably silica, glass, calcium carbonate, titanium dioxide, mica, and a particle unit is preferably about 0.1W about 200 micron in size. The reagent layer consisting of the particle unit is capable of having a gap capacity determined arbitrarily within a range of 20W85%. The particle unit is formed by coating a hydrophilic high-molecular material on a surface of a nuleus of an inorganic material by a graft polymerizing method. The hydrophilic high-molecular material forms a particle unit of a strong nulcear shell multilayer construction by reacting it to a silan coupling agent and/or a reacting group of a titanium series coupling agent present on the inorganic material surface. The analyzing element is effectively used in analysis of dystuff, serum and urine.