OPTICAL FIBER LIQUID LEVEL SWITCH

PROBLEM TO BE SOLVED: To provide an optical fiber liquid level switch of which the manufacture cost can be suppressed low.SOLUTION: An optical fiber liquid level switch comprises a lens 5 which captures emitted light from an optical fiber 3 for detection, a reflection mirror 6 which is disposed at a position opposed to the lens and which is irradiated with emitted light from the lens, a diaphragm 7, and a shading body 8 which is mounted onto the diaphragm. The diaphragm 7 can be deformed by pressure of a liquid, and the shading body 8 can enter a clearance between the lens 5 and the reflection mirror 6 while being interlocked to the deformation of the diaphragm 7 and can shade an optical path therebetween.