Strain gauge

1. A strain gauge comprising:

a substrate formed of resin and having flexibility;

a functional layer formed from a metal, an alloy, or a metal compound, directly on one surface of the substrate;

a resistor formed as a film containing Cr, CrN, and Cr 2 N, on one surface of the functional layer; and

an oxidation impeding layer formed to cover a non-oxidized surface corresponding to an upper surface of the resistor, and to expose a side surface of the resistor,

wherein the oxidation impeding layer is patterned into a same planar shape as the resister,

wherein the register is formed with α-Cr as a main component,

wherein the functional layer includes a function of promoting crystal growth of α-Cr and forming an α-Cr based film.

2. The strain gauge as claimed in claim 1 , further comprising:

a pair of terminal sections extending from both ends of the resistor,

wherein the resistor has a shape that extends in a zigzag way from one of the pair of terminal sections and is connected to the other of the pair of terminal sections, and

wherein the oxidation impeding layer is patterned into a same planar shape as the shape to cover the non-oxidized surface.

3. The strain gauge as claimed in claim 1 , wherein a material of the oxidation impeding layer is Ti.

4. The strain gauge as claimed in claim 3 , wherein a thickness of the oxidation impeding layer is 1 nm to 100 nm.

5. The strain gauge as claimed in claim 1 , wherein a material of the oxidation impeding layer is TiN.

6. The strain gauge as claimed in claim 5 , wherein a thickness of the oxidation impeding layer is 1 nm to 10 nm.

7. The strain gauge as claimed in claim 1 , wherein an element contained in the functional layer is diffused into the film contacting Cr, CrN, and Cr 2 N, and

wherein a gauge factor of the strain gauge is greater than or equal to 10.