Mechanical forces acting on cells have been recognized as an important aspect of cells' environment because cells adjust their cellular functions in response to such forces, including fluid shear force. For studying such mechanobiological responses of cells, multi-well plate microchannel devices have been used to apply flow shear stress on a cell culture for a long duration. The device includes microfluidic channels attached to the bottom of a conventional multiple-well plate. Such readily available multiwell plate channel devices are costly, and they allow neither direct access to cells cultured in the channel nor easy modification of the device. In this paper, we propose an easy-to-adopt, cost effective fabrication method for a multi-well plate channel device with reversible seals. This device consisted of two modules. For the top module, a conventional 24-well plate was modified as the base. An inlet/outlet layer and a channel layer were fabricated using polydimethylsiloxane (PDMS) and soft lithography, and they were permanently bonded to the bottom of the plate. The bottom module was a detachable flow chamber layer made with Ecoflex, PDMS, and transparent film using soft lithography. Since Ecoflex can form weak bonding to PDMS, the flow chamber layer could be easily attached to, and then detached from, the PDMS layer of the top module. As a proof-of-concept, we fabricated a prototype device and tested it by flowing dyed water through the device. No leaking was observed. Then, the device was disassembled and then reassembled for further testing. The weak bonding between Ecoflex and PDMS could create leak-free, reversible seals for the device. The proposed method has the following advantages. First, fabrication of the device is cost-effective because it can be easily created using common lab instruments and inexpensive materials. Second, the proposed method allows easy modification of the channel design. Last, the reversible seal between the two modules allows direct access to a cell culture for further analysis of the sample after flow stimulation.