A surgical support apparatus (1, 2, 3, 4, 5) comprising: a surgical instrument (200, 210) including a treatment portion (202, 203, 213); a holding portion (21A, 21B) whose proximal end portion is connected to a base; a positioning portion having a fixing portion which is fixed to a distal end portion of the holding portion (21A, 21B) to connect the holding portion (21A, 21B), and having a removable portion (52A, 52B) to which the surgical instrument (200, 210) is capable of being attached, and being configured to move the treatment portion (202, 203, 213) relative to the fixing portion; an input section configured to issue operating commands based on inputs from a user; a reference orientation detecting portion (27A, 27B) configured to detect an orientation of a reference position on the positioning portion based on the operating commands; a displacement detecting section (29A, 29B) configured to calculate an amount of change in a positon and an orientation of the removable portion (52A, 52B) per unit time by calculating a position and an orientation of the removable portion (52A, 52B) with respect to the reference position from an amount of angular displacement detected by the displacement detecting section (29A, 29B) with respect to an orientation of the reference position detected by the reference orientation detecting portion (27A, 27B); a treatment portion position detecting section configured to calculate a moved position and a moved orientation of the treatment portion (202, 203, 213) based on the amount of change which is calculated; and a drive section control section configured to control a drive section which moves the removable portion (52A, 52B) and the treatment portion (202, 203, 213) based on a calculation result of the displacement detecting section (29A, 29B) and the treatment portion position detecting section. a surgical instrument (200, 210) including a treatment portion (202, 203, 213); a holding portion (21A, 21B) whose proximal end portion is connected to a base; a positioning portion having a fixing portion which is fixed to a distal end portion of the holding portion (21A, 21B) to connect the holding portion (21A, 21B), and having a removable portion (52A, 52B) to which the surgical instrument (200, 210) is capable of being attached, and being configured to move the treatment portion (202, 203, 213) relative to the fixing portion; an input section configured to issue operating commands based on inputs from a user; a reference orientation detecting portion (27A, 27B) configured to detect an orientation of a reference position on the positioning portion based on the operating commands; a displacement detecting section (29A, 29B) configured to calculate an amount of change in a positon and an orientation of the removable portion (52A, 52B) per unit time by calculating a position and an orientation of the removable portion (52A, 52B) with respect to the reference position from an amount of angular displacement detected by the displacement detecting section (29A, 29B) with respect to an orientation of the reference position detected by the reference orientation detecting portion (27A, 27B); a treatment portion position detecting section configured to calculate a moved position and a moved orientation of the treatment portion (202, 203, 213) based on the amount of change which is calculated; and a drive section control section configured to control a drive section which moves the removable portion (52A, 52B) and the treatment portion (202, 203, 213) based on a calculation result of the displacement detecting section (29A, 29B) and the treatment portion position detecting section.