The variation of the Kα–Kβ spectrum of a micropinch in an iron plasma of a high-current vacuum spark has been studied at detection in a single discharge using a compact diffusion chamber as a detector. The spatial separation of radiation has been performed by diffraction spectroscopy methods. Signatures of the advanced development of acceleration processes for the electron component as compared to the decay of the micropinch plasma caused by its anomalous heating have been found.