A floating drive mechanism for a medical robot, the floating drive mechanism comprising: an actuator that drives a rod to be able to move forward and backward in a first direction; a manipulation member that operates with driving force of the actuator; and a transmission member that is located between the actuator and the manipulation member and is engaged with the rod to transmit an operation of the rod to the manipulation member, wherein the transmission member is restricted in its displacement having a component in a second direction orthogonal to the first direction, the transmission member is separated from the rod in the second direction and transmitting force in the first direction from the rod to the manipulation member, wherein the transmission member has a transmission receiving portion that receives a part of the manipulation member, and the transmission member comes into contact with the manipulation member located in the transmission receiving portion, thereby allowing an operation of the transmission member in the first direction to be transmitted to the manipulation member, wherein the transmission receiving portion receives the part of the manipulation member so as to absorb a displacement of the part of the manipulation member in the second direction, wherein the floating drive mechanism further comprises a linear motion guide that supports a scale portion of a linear encoder in a movable manner in the first direction, wherein the transmission member is fixed to the scale portion and is provided so as to be movable in the first direction together with the scale portion, wherein the scale portion is disposed to face a housing of the actuator, and a detection unit of the linear encoder is attached to the housing. an actuator that drives a rod to be able to move forward and backward in a first direction; a manipulation member that operates with driving force of the actuator; and a transmission member that is located between the actuator and the manipulation member and is engaged with the rod to transmit an operation of the rod to the manipulation member, wherein the transmission member is restricted in its displacement having a component in a second direction orthogonal to the first direction, the transmission member is separated from the rod in the second direction and transmitting force in the first direction from the rod to the manipulation member, wherein the transmission member has a transmission receiving portion that receives a part of the manipulation member, and the transmission member comes into contact with the manipulation member located in the transmission receiving portion, thereby allowing an operation of the transmission member in the first direction to be transmitted to the manipulation member, wherein the transmission receiving portion receives the part of the manipulation member so as to absorb a displacement of the part of the manipulation member in the second direction, wherein the floating drive mechanism further comprises a linear motion guide that supports a scale portion of a linear encoder in a movable manner in the first direction, wherein the transmission member is fixed to the scale portion and is provided so as to be movable in the first direction together with the scale portion, wherein the scale portion is disposed to face a housing of the actuator, and a detection unit of the linear encoder is attached to the housing. wherein the transmission receiving portion receives the part of the manipulation member so as to absorb a displacement of the part of the manipulation member in the second direction, wherein the floating drive mechanism further comprises a linear motion guide that supports a scale portion of a linear encoder in a movable manner in the first direction, wherein the transmission member is fixed to the scale portion and is provided so as to be movable in the first direction together with the scale portion, wherein the scale portion is disposed to face a housing of the actuator, and a detection unit of the linear encoder is attached to the housing. a linear motion guide that supports a scale portion of a linear encoder in a movable manner in the first direction, wherein the transmission member is fixed to the scale portion and is provided so as to be movable in the first direction together with the scale portion, wherein the scale portion is disposed to face a housing of the actuator, and a detection unit of the linear encoder is attached to the housing.