A substrate transfer robot system teaches a transfer position of a substrate to a substrate transfer robot that transfers the substrate. The substrate transfer robot includes: a hand that transfers the substrate; a movement mechanism that moves the hand in horizontal and vertical directions; and first and second sensors that are provided on the hand and radiates a scanning line in the horizontal and vertical directions, respectively. The substrate transfer robot system includes: a controller that controls the hand and the movement mechanism; and a first portion to be detected and a second portion to be detected. The controller operates the hand to detect the first portion by the first and second sensors and detect the second portion by the second sensor, and calculates and stores the transfer position based on position information of the hand when the first and second portions are detected.