Photo-electronic position-measuring device

In a photoelectric position measuring the relative displacement of a trained as a phase grating scanning grating (5) relative to a formed as a reflective phase grating scale (6) is detected, wherein at least one light source (1, 2) emitted light at the scanning grating (5), in the reflection on the scale (6) and finally diffracted again on the scanning grating (5) and detected from the resulting interference pattern only groups with specific diffraction order via photoreceptor (9 to 12) and in periodically changing in the relative displacement of scanning grating (5) and scale (6), mutually phase-shifted measurement signals are converted. The scale (6) has two juxtaposed graduation tracks (7, 8) offset by 1/8 of the lattice constant,