Provided are a surgical robot arm and a fixed point error correction method therefor allowing for matching with a simple configuration and with less economic burden than the prior art, and even in the absence of a driving source such as a motor. A surgical robot arm (1) is provided with a first moving support arm (10), a vertical motion mechanism (30) for supporting and vertically moving the first moving support arm (10), and a second moving support arm (20) for supporting the vertical motion mechanism. One of the two moving support arms is a horizontal articulated arm having a rotating shaft that moves freely in the horizontal direction so as to be driven by an external force applied to a surgical instrument. The vertical motion mechanism has a sliding means (31) for supporting, sliding and guiding the first moving support arm, and an elastic member (36) for supporting the first moving support arm along a sliding direction of the sliding means. The elastic member is configured to have a spring constant that has been set for supporting the first moving support arm on which the surgical instrument has been mounted, and supporting the external force applied to the surgical instrument.Linvention concerne un bras de robot chirurgical et son procédé de correction derreur de point fixe pouvant correspondre à une configuration simple et ayant un fardeau économique inférieur par rapport à létat de la technique, même en labsence dune source dentraînement telle quun moteur. Un bras de robot chirurgical (1) comprend un premier bras de support mobile (10), un mécanisme de mouvement vertical (30) pour soutenir et déplacer verticalement le premier bras de support mobile (10), et un second bras de support mobile (20) pour soutenir le mécanisme de mouvement vertical. Lun des deux bras de support mobiles est un bras articulé horizontal ayant une tige de rotation qui se déplace librement dans la direction horizontale de façon à être entraînée par une force externe appliquée à un inst
