This paper reports on a characterization of the developer-permeability of negative resist enabling a quick development of a complex microchannel network. The present development technique overcomes the diffusion limited process on the existing embedded microchannel fabrications, since the developer permeates the membrane region (channel ceiling) and the permeated developer dissolves uncross-linked photoresist under themembrane. In this paper, a primary feature of dependence of developer-permeability on process parameters was characterized by employing a cross-linking reaction model. Furthermore, microfluidic device with double-layered microchannel was demonstrated to show the usefulness of the proposed fabrication technique. (C) 2010 Published by Elsevier Ltd.