WATER LEVEL SENSOR

PROBLEM TO BE SOLVED: To obtain a water level sensor superior in resistance to environment by a constitution wherein a pressure transferring chamber is filled with an ultra-soft insulation material and a loading face of a strain gauge and a wire substrate including a bonding wire are covered with the ultra soft insulation material. SOLUTION: A pressure of a silicon gel 7 is raised corresponding to a pressure of a direction X of a pressure detection medium installed in a pressure introduction inlet 2c and the pressure is transferred to a pressure transferring chamber 10, then a sensor chip 3 is deformed. As a result, a resistance of a strain gauge is increased or decreased so that a voltage signal corresponding to the pressure of the pressure detection medium is detected via a bonding wire 12. A loading face of the strain gauge on the sensor chip 3 is set to a face opposite the pressure detection face and is filled with a soft insulation material so that the soft insulation material can be comparatively softened directly insusceptible of the detection medium.