Sensor inlet channel

With the present invention, a micromechanical sensor and a method for manufacturing a micromechanical sensor is described which detects at least a state quantity of a substance. It is provided that the sensor has at least a first region for receiving the substance, as well as an access channel through an exchange of substance between the first and a second region is made possible. The essence of the invention consists in the fact that after the creation of the access channel, the wall of the access channel experiences by an etching or embossing process, a further treatment. In this additional treatment, a surface structure is applied to the wall which can be shaped by the type of treatment or by heat used in the treatment materials or predetermined.