Analytical test piece (10) comprising a support (1) and, disposed on the surface (11) and/or in the interior of the support (1), reagent spots (2), the analytical test piece (10) adapted, when an analyte-containing sample (3) is introduced onto the surface (11) of the support (1), to cause the analyte-containing sample (3) to be brought into contact with and react with the reagent spots (2) disposed on the surface (11) and/or in the interior of the support (1) and produce a detectable substance (a signal substance) or exhibit a detectable property (or signal property), wherein the reagent spots (2) are composed of two or more types of reagent spots (21, 22) constituted of any of two or more types of solutions, each of which exhibits a given function upon mixing with the other, the sample (3) introduced in the surface (11) of the support (1) being brought into contact with the two or more types of reagent spots (21, 22) so as to effect not only mutual mixing of the multiple types of reagent spots (21, 22) but also reacting with the two or more types of reagent spots (21, 22) having been mixed together, thereby forming a signal substance or exhibiting a signal property. This analytical test piece excels in analytical reliability, analytical sensitivity (analytical precision), and storage stability.