A robot controller configured to control an end portion of a multi-degree-of-freedom robot, comprising: a rotating disk (120, 160, 220) which is positioned on the robot and adjacent to a robot end portion for adjusting angle of direction in which the robot end portion makes a translational motion; a first control interface which is positioned at a first position on the rotating disk (120, 160, 220) including at least two switches for direction control receiving a first control input for at least four directions; a second control interface which is positioned at a second position on the rotating disk (120, 160, 220) opposite to the first position including at least two switches for direction control receiving a second control input for at least four directions; and an encoder (140, 180, 240) which interprets the combination of the first and second control inputs as a third control input about the robot end portion and provides the robot with a signal according to the third control input, wherein an input direction in which the robot end portion makes a translational motion is determined based on the rotational position of the rotating disk (120, 160, 220), characterized in that, in a 3-dimensional space expressed in terms of x-, y-, and z-axis, when the first and the second control inputs are inputs of a same direction on the same axis, the encoder (140, 180, 240) interprets the control inputs as a translational motion along the input direction, and a translational motion in a direction other than the input direction is restricted by impedance control, in a 3-dimensional space expressed in terms of x-, y-, and z-axis, when the first and the second control inputs are inputs of the opposite direction to each other on the same axis, the encoder (140, 180, 240) interprets the control inputs as a rotational motion about an axis orthogonal to the same axis, and a rotational motion about an axis other than the same axis is restricted by impedance control, the first switch of the first control interface or the second control interfa ce enables a bidirectional motion along one of the x-, y-, and z-axis, and the seco nd switch of the first control interface or the second control interface enables a bidirectional motion along an axis orthogonal to one axis related to the first switch (1 12), the robot end portion moves upon the exertion of an external force. a rotating disk (120, 160, 220) which is positioned on the robot and adjacent to a robot end portion for adjusting angle of direction in which the robot end portion makes a translational motion; a first control interface which is positioned at a first position on the rotating disk (120, 160, 220) including at least two switches for direction control receiving a first control input for at least four directions; a second control interface which is positioned at a second position on the rotating disk (120, 160, 220) opposite to the first position including at least two switches for direction control receiving a second control input for at least four directions; and an encoder (140, 180, 240) which interprets the combination of the first and second control inputs as a third control input about the robot end portion and provides the robot with a signal according to the third control input, wherein an input direction in which the robot end portion makes a translational motion is determined based on the rotational position of the rotating disk (120, 160, 220), characterized in that, in a 3-dimensional space expressed in terms of x-, y-, and z-axis, when the first and the second control inputs are inputs of a same direction on the same axis, the encoder (140, 180, 240) interprets the control inputs as a translational motion along the input direction, and a translational motion in a direction other than the input direction is restricted by impedance control, in a 3-dimensional space expressed in terms of x-, y-, and z-axis, when the first and the second control inputs are inputs of the opposite direction to each other on the same axis, the encoder (140, 180, 240) interprets the control inputs as a rotational motion about an axis orthogonal to the same axis, and a rotational motion about an axis other than the same axis is restricted by impedance control, the first switch of the first control interface or the second control interfa ce enables a bidirectional motion along one of the x-, y-, and z-axis, and the seco nd switch of the first control interface or the second control interface enables a bidirectional motion along an axis orthogonal to one axis related to the first switch (1 12), the robot end portion moves upon the exertion of an external force.