1. Medical microelectrode for insertion into soft tissue, comprising an electrically conducting elongate electrode body having a first, proximal end and a second, distal end, the electrode body comprising a tip section extending from its distal end, a main body section extending in a proximal direction from the tip section, and, optionally, a coupling section extending in a proximal direction from the main body section, wherein the tip section, the main body section and, optionally, the coupling section are embedded in a first electrode matrix element, which is substantially rigid, biocompatible and soluble or biodegradable in a body fluid, further comprising one or both of:a dissolution retarding layer on the first electrode matrix element;
a second electrode matrix element disposed between the first electrode matrix element and the electrode;
wherein a drug capable of being released upon dissolution or biodegradation of the first electrode matrix element is comprised by the first electrode matrix element or the second electrode matrix element; and
an anchor positioned at the tip section.