SMALL VOLUME -i(IN VITRO) ANALYTE SENSOR

[Subject] The sensor which enables execution of analysis with exact sample concentration in a snug product sample and high sensitivity and which there are few pains and they can use easily comparatively is provided. [Means for Solution] Are sample concentration in a sample an electrochemical sensor to measure, and At least one work electrode, It is a sensor including at least one opposite electrode and at least one sample room, A sample room of a size where the at least one sample room contacts a (i) sample to the work electrode in electrolysis, holds it, and includes a sample below 1microL, or it is a boundary attachment れた measurement region by the work electrode and the pair electrode about at least 2 methods of (ii), and is a sample room including a measurement region of a size containing a sample below 1microL, and a oxidation reduction mediation agent of insoluble 脱性 is included on the work electrode. [Chosen drawing] Drawing 1