The invention relates to a biosensor, comprising: a base substrate which includes a detecting unit for detecting a sample introduced via an electrode; an insulating layer which is positioned on an upper surface of base substrate; an upper plate which is mounted on an upper side of base substrate and includes a plurality of sample introducing units for introducing the sample to an upper side of detection unit to the upper surface; and a spacer which is provided between the upper plate and the insulating layer and forms a chamber.
