Among rich family of iron oxides, the metastable e-Fe2O3 is the most intriguing phase, demonstrating room-temperature ferroelectricity, ferrimagnetism and large magneto crystalline anisotropy. In nanocrystalline form e-Fe2O3 exhibits a low-temperature phase transition accompanied by about 5% diminution in the saturation magnetization a large decrease in the coercivity field between 200 and 100 K. On the other hand, such transitions have never been observed in the epitaxial films by hysteresis loop measurements. However, temperature dependence of magnetization of 50 nm-thick epitaxial film indicates a magnetic phase transition suppressed by the field in field-cooling measurement. This would be interesting to track this transition by diffraction. Noteworthy, the magnetic structure of the e-Fe2O3 epitaxial films has never been explored by means of neutron or resonant X-ray scattering and hence remains unknown. We propose to determine the magnetic structure and track a possible magnetic phase transition of the epitaxial film e-Fe2O3 grown on GaN(0001) buffer.