Abstract: Electrochemical biosensors consisting of two or more needle-shaped electrodes for monitoring of molecules such as glucose in the subcutaneous tissue are provided. The two electrodes are parallel to each other, and are fixed perpendicularly to the planar side of a sensor base which provides skin fixation and electric connection. The needle electrodes are made of rigid conducting materials, capable of inserting into the skin without the need of catheters. One electrode is the sensing electrode and the other, the reference electrode. A compound sensing membrane is attached onto the sensing electrode surface to detect analyzed molecules.