A method for manufacturing an electrode assembly, the method comprising: a step (a) of transferring a plurality of radical units, in which a first electrode, a separator, a second electrode, and a separator are sequentially stacked, one by one from a first set position to a second position; a step (b) comprising a process of measuring a distance, in which the radical units are photographed at the first set position to measure a distance between a full width end that is an end of the first electrode in a full width direction and a full width end that is an end of the second electrode in a full width direction, which are provided in the photographed first radical unit, a distance between a full width end that is an end of the first electrode in a full width direction and a full width end that is an end of the second electrode in a full width direction, which are provided in the photographed second radical unit, and a distance (An) between a full width end that is an end of the first electrode in a full width direction and a full width end that is an end of the second electrode in a full width direction, which are provided in the photographed n-th radical unit; a step (c) comprising a process of measuring a distance, in which, when the first radical unit, at which the distance is measured, is transferred to the second set position, the distance from a reference point of the second set position to the full width end of the first electrode of the first radical unit is measured; a step (d) of stacking the second radical unit, which is transferred to the second set position via the first set position, on the first radical unit; a step (e) comprising a process of measuring a distance from the reference point of the second set position to the full width end of the first electrode of the second radical unit; a step (f) comprising a process of measuring a distance between the full length end of the first electrode of the first radical unit and the full width end of the second electrode of the second radical unit by adding the distances (B2, A2) to each other and subtracting the distance from the sum of the distances (B2, A2); and a step (g) comprising a full width inspection process, in which the distances (C1, A1) are compared to each other to determine that the stacking is normal when a difference value between the distances (C1, A1) is within an input error value, and the stacking is defective when the difference value is out of the input error value. a step (a) of transferring a plurality of radical units, in which a first electrode, a separator, a second electrode, and a separator are sequentially stacked, one by one from a first set position to a second position; a step (b) comprising a process of measuring a distance, in which the radical units are photographed at the first set position to measure a distance between a full width end that is an end of the first electrode in a full width direction and a full width end that is an end of the second electrode in a full width direction, which are provided in the photographed first radical unit, a distance between a full width end that is an end of the first electrode in a full width direction and a full width end that is an end of the second electrode in a full width direction, which are provided in the photographed second radical unit, and a distance (An) between a full width end that is an end of the first electrode in a full width direction and a full width end that is an end of the second electrode in a full width direction, which are provided in the photographed n-th radical unit; a step (c) comprising a process of measuring a distance, in which, when the first radical unit, at which the distance is measured, is transferred to the second set position, the distance from a reference point of the second set position to the full width end of the first electrode of the first radical unit is measured; a step (d) of stacking the second radical unit, which is transferred to the second set position via the first set position, on the first radical unit; a step (e) comprising a process of measuring a distance from the reference point of the second set position to the full width end of the first electrode of the second radical unit; a step (f) comprising a process of measuring a distance between the full length end of the first electrode of the first radical unit and the full width end of the second electrode of the second radical unit by adding the distances (B2, A2) to each other and subtracting the distance from the sum of the distances (B2, A2); and a step (g) comprising a full width inspection process, in which the distances (C1, A1) are compared to each other to determine that the stacking is normal when a difference value between the distances (C1, A1) is within an input error value, and the stacking is defective when the difference value is out of the input error value.