Abstract: An ion guide electrode assembly (10) for an ion-mobility spectrometer is described. The electrode assembly (10) comprises a first sheet (100), having first and second surfaces (110, 120) comprising a plurality of corresponding regions (111, 112, 121, 122). The first sheet (100) comprises a set of N electrodes (130, 140), including a first electrode (130) and a second electrode (140), provided as tracks mutually spaced apart on the first surface (110) thereof. The electrode assembly (10) is arrangeable in a planar configuration and preferably in a tubular configuration. In the tubular configuration, a first part (131) of the first electrode (130), provided in a first region 111 of the first surface (110), overlays a second region (122) of the second surface (120).