The present invention relates to a process for recovering lactide from polylactide (PLA) or glycolide from polyglycolide (PGA), in which, in a first step, PLA or PGA is contacted with a hydrolysing medium and hydrolytically degraded to oligomers. In a further step, a cyclising depolymerisation of the oligomers obtained in the first step is effected to give lactide or glycolide. In addition, the present invention relates to an apparatus based on the combination of a hydrolysis apparatus with a depolymerisation reactor, with which the above-described process can be performed. The core of the process according to the invention is a partial hydrolysis of the polymeric materials originally used in combination with a cyclising depolymerisation.