Following with our studies on the characteristics of energy release in solar flares we include in our analysis the weak brightening called "microflares". With the observations from the Hard X-ray Imaging Spectromter (HXIS) that flew aboard the Solar Maximum Mission Satellite (SMM) we analyzed the active region 2779 which pass through the solar disk on November 1980. All the events present very similar properties in spite of their large differences in X-ray intensities. The topology of the energy release region is preserved over a period in which an active region produced numerous events, except at the site of a two-ribbon flare, which probably led to a permanent disruption of the magnetic configuration.