Focusing properties of the inverse‐radial potential in the spherical electrostatic analyzer for charged particles having relativistic speeds are calculated by a first‐order method valid for large values of &bgr;=v/c.Extending similar calculations of focusing by the logarithmic potential in the cylindrical analyzer, the treatment stresses deviations from focusing properties for low speed particles, and emphasizes analogies between the characteristics of focusing accomplished by each type of field, wherever possible. Approximate formulas are given by which the diameter of the region of least confusion may be computed for several interesting situations.