The ATM (Automatic Thickness Measuring) Instrument is a non-contact, high-speed, high-precision, and professional-grade thickness measuring equipment for lenses and other precision parts. It is suitable for detection of thickness < 15mm, and automatically detects a single point of measurement on the testing sample. It adopts advanced design concepts and hardware configuration to measure the value of the thickness of the testing sample and to make the judgement of pass/fail automatically, improving detection efficiency.