Abstract: The present invention is to provide an electrical urea biosensor and its manufacturing method. In the present invention, a sensitive film is positioned on a surface of a substrate, wherein a conductive layer is formed on the surface of the substrate. The sensitive film is used as an ion-sensitive electrode. The sensitive film provides with a sensitive region and a non-sensitive region. A conductive line is extended from the conductive layer for using as an external electrical contact point. The present invention utilizes a package encapsulant covering the non-sensitive region of the sensitive film to define a sensitive window at the sensitive region and a urea enzyme is immobilized within the sensitive window of the sensitive film. Then, the present invention completes the formulation of a urea biosensor. The present invention is a disposable urea biosensor and provides with advantages of the mass production, low cost, and the easy package.