A medical manipulator according to an embodiment may include an arm base including a first engagement portion and a manipulator arm including a distal end portion to support a surgical tool and a proximal end portion including a second engagement portion. One of the first and second engagement portions includes a shaft member and the other includes an engagement member engageable with the shaft member such that the engagement member engaged with the shaft member is rotatable with respect to the shaft member. The arm base includes a restriction portion to restrict rotation of the manipulator arm about the shaft member to which the engagement member is engaged. The proximal end portion of the manipulator arm is fixed to the restriction portion of the arm base with a fixing member in a state where restriction portion stops the rotation of the manipulator arm.