Abstract: A modular wall system adapted for use as part of a clean room structure, comprising a plurality of unibody panel sections, each panel section having a uniform width and including an exterior face, an interior face, and laterally opposing assembly flanges extending along the length of each edge of the panel section. Each assembly flange includes (i) a flange side wall extending inward from the interior face, (ii) an interlocking member adapted to be engaged with another interlocking member of a separate panel to secure the two flanges together, and (iii) a sealing member for sealing openings between coupled assembly flanges. A support channel configured in size and shape for snug fit around the coupled assembly flanges includes a channel cap and side channel walls which extend for equal lengths sufficient to abut against the interior faces of the coupled panel sections. These side walls operate as spacer members for aligning panel sections as the assembly flanges are secured within the support channel.