Patent ID: 7437907

Claim:
A sensor for detecting a substance in liquid, comprising: a base substrate; at least one SAW element disposed on one surface of the base substrate, including a surface acoustic wave substrate and at least one IDT electrode disposed on one surface of the surface acoustic wave substrate, a portion of the at least one SAW element including said at least one IDT electrode defining a sensing portion; a resin layer arranged to cover the one surface of the base substrate and an external surface of the at least one SAW element, the resin layer having an opening in which the sensing portion of the at least one SAW element is exposed at the one surface side of the base substrate; and a reaction film arranged to cover the sensing portion of said at least one SAW element, the reaction film being made of a material that binds to a detection target substance; wherein the base substrate includes at least one recess and said at least one SAW element is disposed in said at least one recess.