Substrate gripping apparatus, substrate gripping method and substrate releasing method

A robot hand 23 having a hand body 30 having a reference axis J 1 is provided with fixed holding members 40 and 41 and a movable holding member 42. The holding members 40, 41 and 42 are arranged on the hand body at angular intervals about the reference axis J 1 . Each of the fixed holding members 40 and 41 has a first guide part 50 and a second guide part 51 defining a V-shaped groove. The movable holding member 42 has a first guide part 60 and a second guide part 61 defining a V-shaped groove. Peripheral parts 19 of a wafer 22 are fit in the V-shaped grooves of the holding members 40 to 42 to grip the wafer 22 by the robot hand 23 . The first guide parts 50 and 61 are provided at their lower ends with protrusions 55 and 65 protruding toward the reference axis J 1 , respectively. The protrusions 55 and 65 prevent the wafer 22 from slipping off the holding members 40 to 42.