Abstract: The invention provides an apparatus for forming moulded articles such as removable insoles for shoes. A blank is placed between a rigid plate corresponding to the peripheral base contour of the finished article on one side thereof and a mould bed corresponding to the shape of the article on the other side thereof. Peripheral areas of the blank are exposed by the plate and a flexible diaphragm is applied over the plate under pressure or with the aid of a vacuum after heating the blank to the softening point, to define said peripheral base contour, and to conform the other side and the exposed areas of the blank to the shape of the mould bed. In the case of shoe insoles, a range of sizes can be made with the same mould bed, using only different sizes of plate.