A tube insertion device which inserts a tube into a line path to perform an operation has an elongated hollow tube, an end effector connected to a front end of the tube such that the direction of the end effector is changed with respect to the tube, a plurality of wires connected to the end effector and extended into the tube and a tension controller controlling tensions of the plurality of wires. The tension controller controls tensions of a pair of wires facing each other in the opposite directions, in order to change the direction of the end effector.