In the considered method of the H−beam diagnostics the information on beam parameters is taken out via the fast H° atoms which are produced in definite quantum states at the charge‐exchanging area of the transport line. The beam parameters are determined in the convenient area outside the transport line by means of a compact magnetic analyzer and electrons produced from a selective photoionization of the useful quantum state of the H° atoms. The realization of such diagnostics at the area of the charge‐exchanging H−→P injection of the meson factory storage rings is considered. If the information on the H−beam parameters is taken out via the fast H° atoms in metastable 2s‐quantum state the accuracies of correspondence between electron and ion distributions ≊10−2% in energy and ≊3×10−5rad in angle coordinate can be obtained.