An oil transformer insulation module includes a plurality of disc-like insulation elements of identical type which are arranged flush one above another along a line, connected to one another and have in each case at least a similar outline contour. An insulation element includes a first flat layer and a second layer adjacent and predominantly parallel thereto. The first and second layers are composed of a mechanically strong, planar first insulation material. The first and second layers of the first insulation material are connected to and spaced apart from a third, corrugated layer arranged between the first and second layers and composed of a mechanically strong, planar second insulation material. The third layer has lateral edges and is corrugated in such a way that all the cavities formed by the corrugated form can be completely flooded with a liquid via the lateral edges of the insulation element.