Patent ID: 8349157

Claim:
A method of manufacturing a biosensor for quantifying a substrate in a sample liquid comprising: providing an insulating support; providing an electrically conductive layer that is made of a noble metal on a surface of the insulating support; forming an electrode pattern comprising at least a working electrode and a counter electrode from the electrically conductive layer by dividing the electrically conductive layer using a laser to form the working electrode and the counter electrode; providing a reagent layer formed on the electrode pattern; providing a spacer layer on and covering part of the reagent layer, where the spacer layer defines a supply path for bringing the sample liquid into contact with the reagent layer and where the supply path formed by the spacer layer is narrower than the reagent layer; and providing a cover on the spacer layer; wherein an area of the counter electrode and an area of the working electrode are in the supply path, and the area of the counter electrode in the supply path is equal to or larger than the area of the working electrode in the supply path, and wherein part of the reagent layer is in the supply path.