Patent ID: 7727367

Claim:
A biosensor comprising: in its tip portion, an electrically insulating substrate and a cover sheet facing each other with a space in between and a spacer sheet somewhere therebetween; and a reaction part having an oxidoreductase in a holding space formed by the substrate, the cover sheet and a spacer sheet end; the liquid sample being delivered from the tip of the sensor into the holding space by capillary action, and an electrochemical change caused by an enzyme reaction between the liquid sample and the reaction part being detected using an electrode set having a working electrode and a counter electrode; the biosensor being provided with a projection at only one side in the widthwise direction of the spacer sheet end in the holding space with the projection extending toward the tip portion of the biosensor; the biosensor lacking an outlet for discharging gas in the holding space; the spacer sheet consisting of one sheet; and the electrode being disposed on the substrate.