This article describes the opportunities microstructured reactors offer for chemical plant engineering. This suitability for chemical production is commonly regarded to be the key to market penetration. Century-long practices with batch-type stirring and, correspondingly, the existence of capital-intensive large-scale plants, hinder an easy and fast implementation of chemical micro process engineering. Seen in the long term, there is potential that new plants can be equipped with microstructured reactors. Only economic balances, however, which draw up profitability, will open the door to the usage of chemical micro process engineering for plant construction. The main arguments for using microstructured reactors are enhanced conversion and selectivity, increased space-time yields, waste reduction and better safety given the small reactor volumes. Credit-card sized reaction systems allow one to perform the screening of multi-step reactions in one run. Even more impressively, similar screening is carried out for single-step reactions faster and more reliably. Moreover, safe processing with microstructured reactors in the explosive regime enlarges the traditional range of processing. The reaction guidance by microstructured reactors can further influence subsequent processing steps, such as product purification, and in this way can lower the energy costs of processes.