A lawn mower robot configured for being operated in a work area defined by a boundary indication unit including a boundary wire; and comprising: a main body configured to move within the work area defined by the boundary wire, wherein the main body includes: sensing units configured to sense voltage values induced by the boundary wire; and a controller configured to determine a distance between the main body and the boundary wire from the voltage values sensed by the sensing units, wherein: each sensing unit includes a first coil, a second coil and a third coil differently installed; and the first coil, the second coil and the third coil are arranged such that three axes of the coils are respectively perpendicular to one another, and configured to sense voltage values induced by the boundary wire, the first coil and the second coil are configured to acquire information regarding the distance between the boundary wire and the main body when the main body travels within the work area, the third coil is configured to be installed to be wound in the upward direction of the main body, and to acquire information as to whether or not the main body is present at the inside or outside of the closed loop by the boundary wire, characterized in that the controller is configured to determine the distance by summing the voltage values sensed by the first coil and the second coil, and to maintain the distance between the main body and the boundary wire so that the sum of the voltage values sensed by the first coil and the second coil is regularly maintained. a main body configured to move within the work area defined by the boundary wire, wherein the main body includes: sensing units configured to sense voltage values induced by the boundary wire; and a controller configured to determine a distance between the main body and the boundary wire from the voltage values sensed by the sensing units, wherein: each sensing unit includes a first coil, a second coil and a third coil differently installed; and the first coil, the second coil and the third coil are arranged such that three axes of the coils are respectively perpendicular to one another, and configured to sense voltage values induced by the boundary wire, the first coil and the second coil are configured to acquire information regarding the distance between the boundary wire and the main body when the main body travels within the work area, the third coil is configured to be installed to be wound in the upward direction of the main body, and to acquire information as to whether or not the main body is present at the inside or outside of the closed loop by the boundary wire, characterized in that the controller is configured to determine the distance by summing the voltage values sensed by the first coil and the second coil, and to maintain the distance between the main body and the boundary wire so that the sum of the voltage values sensed by the first coil and the second coil is regularly maintained. sensing units configured to sense voltage values induced by the boundary wire; and a controller configured to determine a distance between the main body and the boundary wire from the voltage values sensed by the sensing units, wherein: each sensing unit includes a first coil, a second coil and a third coil differently installed; and the first coil, the second coil and the third coil are arranged such that three axes of the coils are respectively perpendicular to one another, and configured to sense voltage values induced by the boundary wire, the first coil and the second coil are configured to acquire information regarding the distance between the boundary wire and the main body when the main body travels within the work area, the third coil is configured to be installed to be wound in the upward direction of the main body, and to acquire information as to whether or not the main body is present at the inside or outside of the closed loop by the boundary wire, characterized in that the controller is configured to determine the distance by summing the voltage values sensed by the first coil and the second coil, and to maintain the distance between the main body and the boundary wire so that the sum of the voltage values sensed by the first coil and the second coil is regularly maintained. each sensing unit includes a first coil, a second coil and a third coil differently installed; and the first coil, the second coil and the third coil are arranged such that three axes of the coils are respectively perpendicular to one another, and configured to sense voltage values induced by the boundary wire, the first coil and the second coil are configured to acquire information regarding the distance between the boundary wire and the main body when the main body travels within the work area, the third coil is configured to be installed to be wound in the upward direction of the main body, and to acquire information as to whether or not the main body is present at the inside or outside of the closed loop by the boundary wire, characterized in that the controller is configured to determine the distance by summing the voltage values sensed by the first coil and the second coil, and to maintain the distance between the main body and the boundary wire so that the sum of the voltage values sensed by the first coil and the second coil is regularly maintained.