Described herein is a microreactor for carrying out chemical reactions between a reaction partner in liquid form and a reaction partner in gaseous form, if necessary in the presence of a solid catalyst, whereby the chemical process guidance takes place in spaces that are formed by two or more essentially coplanar plates or layers, with at least one of these plates or layers being a fluid guidance plate (1) that is structured and/or arranged in such a way that the fluid reaction partner flows in at least one essentially uninterrupted capillary thread along the surface of this plate or layer only due to the influence of gravity and/or capillary forces and thereby comes into contact and reacts with the gaseous reaction partner.