This paper uses an unbalanced panel data set for exporting firms from manufacturing industries in one German federal state, Lower Saxony, to investigate the micro-structure of the recent export boom. Looking at data for 1995/96 to 2001/02 it is demonstrated that a considerable number of plants starts and stops exporting in each year, but that most of the export dynamics is due to positive and negative changes of exports in plants that continue to export. A small fraction made of four to five percent of all exporting plants is responsible for around 70 to 80 percent of the gross increase in exports. Firms with expanding and contracting exports are found simultaneously in all broad sectors, technology classes and firm size classes. Patterns of export behavior differ widely between the plants over the periods investigated.