Method and device for monitoring surface condition

Surface state monitoring device, comprising: an infrared radiation source (20), a first infrared ray collecting device (30) for collecting infrared radiation from the infrared radiation source (20) is emitted, on an outer peripheral portion (14) of a monitoring at the substrate (12) and to be monitored for introducing the infrared radiation into the substrate, an incident angle controller (80) for controlling the angle of incidence of the infrared radiation that has been collected from the first infrared ray collecting device (30), and in that to monitor substrate (12) occurs, prescribed on a fixed or variable value; a second infrared ray collecting device (40) for collecting the infrared radiation to be monitored in the substrate (12) has undergone multiple reflections, and to monitor substrate (12) exits; an infrared radiation detector means (50, 52) were collected for detecting the infrared rays from the second infrared ray collecting device (40); and an infrared radiation analysis apparatus (60) for examining the detection information from the infrared radiation detector means (50, 52) was generated to determine contaminants on the surfaces of the monitored substrate (12) available ...