An absolute encoder comprising a sensor array, a code plate arranged in opposition to the sensor array and having a plurality of blocks in the direction of normal displacement, each block having an address track and a fine reading track, and an arithmetic unit for processing data of the code plate detected by the sensor array. Each of the blocks of the code plate has a reference track, an address track and a fine reading track. The fine reading track of each block has fine reading patterns which change in a direction crossing said direction of normal displacement.