1. A moving distance sensing apparatus for a robot cleaner, comprising: a plurality of long distance sensors, each configured to sense a distance with its own sensing area, wherein a sum of respective sensing areas of the long distance sensors corresponds to an entire sensing area of the robot cleaner; a plurality of short distance sensors, mounted on the same sensing lines in one-to-one correspondence with the plurality of long distance sensors for the same directions, respectively, each configured to sense a distance with its own sensing area, wherein a sum of respective sensing areas of the short distance sensors corresponds to an entire sensing area of the robot cleaner; and a microcomputer configured to determine a precise moving distance and a moving distance error based on distance information with respect to the sensing areas of the long distance sensors and the short distance sensors, wherein as the robot cleaner gets close to or away from a predetermined cleaning path or an arbitrary path, the microcomputer compares a moving distance rate sensed by the long distance sensors with a moving distance rate sensed by the short distance sensors, and determines a moving distance error depending on the compared result.