The microreactor consists of a pre-heating line for two reagents, a mixer and a holding line for the mixed product. The mixing elements are very simply structured by means of "chicanes" (Design element "Type S"), which makes them especially suitable for use with precipitation reactions and suspensions. In this reactor the temperature is adjusted by means of an external thermostat by a simple "immersion" of the reactor. This avoids losses in the supply lines and more extreme temperatures can be achieved.