| 摘要 |
<p>Provided is a temperature measuring method capable of correctly measuring a temperature by using interference of low coherence light even if foreign bodies deposit on a temperature measuring object. Data indicating the relationship between an optical path length of a predetermined path, and a temperature of a focus ring (25) is created, and the optical path length is obtained when low coherence light travels the predetermined path inside the focus ring (25) by using optical interference of reflected light when the low coherence light actually irradiates the focus ring (25) arranged in a substrate processing device (10), and the temperature of the focus ring (25) is obtained by comparing with the data. In the predetermined path, low coherence light enters into the focus ring (25) from a back side not changed according to time with respect to the focus ring (25), and a course thereof is changed in an inclined surface (25a) to travel toward a wall surface (25b) not changed according to time with respect to the focus ring (25), and the low coherence light is set to return to a trajectory where low coherence light travels after being reflected by the wall surface (25b).</p> |
