The invention concerns a medium frequency transformer with a housing, in which numerous winding chambers, having primary and secondary windings, are disposed, wherein the housing is filled, at least partially, with an insulating liquid. The transformer is distinguished in that numerous winding chambers, filled with the insulating liquid, are disposed in the housing, and at least one winding is disposed in each winding chamber, such that, for the most part, only the windings are surrounded by the insulating medium. Preferably the winding chambers are sealed and separated from one another by means of insulating separating walls, wherein the windings are positioned and fixed in place in the winding chambers, and the winding chambers are filled with the insulating liquid. Between the windings there are thus, according to the invention, at least two insulating barriers, which function simultaneously and consist of solid matter insulation in the form of housing and separating walls, and the insulating liquid.