A review of emittance measurement methods of the accelerated (ionic or electronic) beams on various accelerating facilities both foreign, and Ukrainian is presented. There are some ways of emittance measurements in their various modifications: a slit method ("two slits", "four slits", Allison scanner), pepperpot method, and also gradient method (quadrupole scanning). The most high-speed and exact enough way of emittance measurement what is pepperpot method in detail considered on example UNILAC GSI (Darmstadt, Germany). Possibility of a field angular distribution use in a distant zone of an optical diffraction radiation made electronic bunch, passing through rectangular apertures in screens (DESY, Hamburg, Germany) is shown.