A biochemical analysis unit comprises a base plate, which has holes, and a porous adsorptive material, which is filled in each of the holes and forms each of adsorptive regions. Each of the adsorptive regions is provided with a layer, which has pores having a comparatively small mean pore diameter, and a layer, which has pores having a comparatively large mean pore diameter. In cases where the layers, which constitute each of the adsorptive regions, are connected with the layers, which constitute an adjacent adsorptive region, at one of surfaces of the base plate, the biochemical analysis unit further comprises a signal absorbing layer for absorbing a signal, which passes through layers located under the base plate and thus propagates from a certain hole toward an adjacent hole.