US Patent 11476138 Diagnostic system of substrate transfer hand

A diagnostic system of a substrate transfer hand including a base part coupled to a hand tip portion of a robot arm and a substrate holding part coupled to the base part to hold a substrate, includes a camera which is secured to the base part and takes an image of the substrate holding part; and a diagnostic device which obtains image information of the image taken by the camera and diagnoses normality of the substrate holding part based on the image information.