An optical encoder, comprising a plurality of light receiving elements 1-12, receiving light that has passed through or been reflected by a scale having a lattice of pitch P, and outputting four-phase signals that have been respectively offset in phase by an integer number of times 90 DEG (1/4P). 12 light receiving elements being are in the lateral direction (scale longitudinal direction) with gaps between them of P/60 or 2P/60, four arbitrary light receiving elements arranged next to each other in a row all output signals of different phases, and light receiving elements respectively outputting signals of same phase have three lateral widths of 7P/60, 13P/60 or 20P/60.