The present invention provides a truss device for an escalator or moving walk comprising an outer panel and an inner panel facing the outer panel, characterized in that, the inner panel is formed from a single integral panel and comprises a body part and a plurality of connection parts extending from the body part toward the outer panel thus forming corresponding through openings in the inner panel, each connection part is connected to the outer panel so that the outer panel and the inner panel are fixed together, wherein the inner panel further comprises a support part formed on the body part of the inner panel and projecting in a direction away from the outer panel. The present invention also provides an escalator or moving walk having the above truss device.