A medical operation apparatus for a master- slave robot configured to acquire an operation performed by an operator, the medical operation apparatus comprising: a body (10; 60) configured to be grasped by the operator; an operation part formed into a long shape and arranged so as to enable at least a part of the operation part to be moved closer to and away from the body (10, 60) by the operator; a detector configured to detect an angle between the body and the operation part and output the detected angle; and a holder (30; 70) configured to hold fingers of the operator grasping the body (10, 60), the holder (30, 70) being configured to transmit a movement of the fingers to the operation part, wherein the holder (30, 70) comprises: a contact portion (33; 73) configured to be in contact with the body (10, 60) when the operation part is moved closer to the body (10, 60), and a connector (31, 71) supporting a relative posture of the holder (30, 70) and the operation part so as to change the relative posture in accordance with a posture change of the fingers of the operator, wherein the connector (31, 71) connects the holder (30, 70) and the operation part so that an arrangement position of the holder (30, 70) along a longitudinal direction of the operation part having the long shape is changeable, and wherein the contact portion (33, 73) or the body (10, 60) is configured such that, in a relative arrangement position of the body (10, 60) with which the contact portion (33, 73) is in contact and the operation part, when the relative posture of the holder (30, 70) and the operation part is changed, an amount of change in the relative arrangement position of the body (10, 60) and the operation part is within a specified permissible range. a body (10; 60) configured to be grasped by the operator; an operation part formed into a long shape and arranged so as to enable at least a part of the operation part to be moved closer to and away from the body (10, 60) by the operator; a detector configured to detect an angle between the body and the operation part and output the detected angle; and a holder (30; 70) configured to hold fingers of the operator grasping the body (10, 60), the holder (30, 70) being configured to transmit a movement of the fingers to the operation part, wherein the holder (30, 70) comprises: a contact portion (33; 73) configured to be in contact with the body (10, 60) when the operation part is moved closer to the body (10, 60), and a connector (31, 71) supporting a relative posture of the holder (30, 70) and the operation part so as to change the relative posture in accordance with a posture change of the fingers of the operator, wherein the connector (31, 71) connects the holder (30, 70) and the operation part so that an arrangement position of the holder (30, 70) along a longitudinal direction of the operation part having the long shape is changeable, and a contact portion (33; 73) configured to be in contact with the body (10, 60) when the operation part is moved closer to the body (10, 60), and a connector (31, 71) supporting a relative posture of the holder (30, 70) and the operation part so as to change the relative posture in accordance with a posture change of the fingers of the operator, wherein the connector (31, 71) connects the holder (30, 70) and the operation part so that an arrangement position of the holder (30, 70) along a longitudinal direction of the operation part having the long shape is changeable, and wherein the contact portion (33, 73) or the body (10, 60) is configured such that, in a relative arrangement position of the body (10, 60) with which the contact portion (33, 73) is in contact and the operation part, when the relative posture of the holder (30, 70) and the operation part is changed, an amount of change in the relative arrangement position of the body (10, 60) and the operation part is within a specified permissible range.