Diamond window is high quality synthetic diamond (Type II a ) that we can use for wide range from UV to Far-IR. There are many kind of windows for transmission measurement with IR microscope such as KBr, BaF2 etc However those windows are easy to scar and some materials are deliquesce. Typical windows are consumable parts. Diamond window is durable, easily to cleaning and it can use for semi-permanent. Also it is high throughput for mid-IR region. Easy to see the sample with transparent sample with diamond window. This windows are appropriate for micro sampling for IR Microscope.