Environmental control and life support, ultimately tied to the presence of man in space is one of the key issues of the permanently manned space station initiated by the USA , .*Europe's participation in that programme is the COLUMBUS programme, the various elements and scenarios of which were subject of extensive studies , , .This paper is devoted to the Environmental Control and Life Support Subsystem (ECLSS) of the Pressurized Module (PM), the latter being one of the COLUMBUS elements.The present COLUMBUS scenario for the PM comprises the PM either to be attached to the US Space Station (USSS), being one of the core elements of the USSS (integrated PM) or as a Man Tended Free Flyer (MTFF, a PM docked to the Resource Module, RM).The PM in the attached configuration is shown in Fig. 1.The present considerations center on the ECLSS of the PM in attached version which is taken as baseline. Reference is made to the ECLSS of integrated PM respectively MTFF only to point out specific differences.In the first part of the paper the specific characteristics of the COLUMBUS ECLSS versus the SPACELAB ECLSS are worked out. Starting point is an analysis of the requirements followed by the formulation of guidelines for a system approach to COLUMBUS ECLSS.The aim is to precisely identify the differences between COLUMBUS and SPACELAB.In the light of the guidelines the presently elaborated conceptual design of the COLUMBUS PM ECLSS is presented.Coherent with the system approach for ECLSS the field of required technology development comes into discussion. In a separate chapter these technological areas are identified and the involved hardware activities are highlighted.The implementation of the technological concepts forms a further point in the considerations on technology development.