| 摘要 |
<p>Provided is an apparatus for measuring consumption capable of measuring consumption with a simplified configuration with respect to a member whose thickness cannot be directly measured. A consumption measuring apparatus (40) is capable of branching low-coherence light output from a low-coherence light source (41) into two paths when consumption of an upper electrode plate (27) arranged inside a chamber (11) of a substrate processing apparatus (10) is calculated. Reflected light is received from an upper surface and a lower surface of the upper electrode plate (27) when the low-coherence light transmitted to one path is irradiated to a measurement point B1 of the upper electrode plate (27), and reflected light is received from an upper surface and a lower surface of the upper electrode plate (27) when the low-coherence light transmitted to the other path is irradiated to a measurement point B2 of the upper electrode plate (27). Moreover, intensity distribution depending on the wave number with respect to the received reflected light is detected, and a spectrum representing the intensity distribution is Fourier transformed. Therefore, the thickness difference between the measurement points B1 and B2 is calculated by the optical path difference.</p> |
