This is a short summary of research on the self-magnetically Bθ-insulated ion diode originally proposed by K. Zieher (1981, 1983, 1984, 1984a). We report the most recent progress. For detailed discussions see the forthcoming publications (Schimassek 1989; Westermann 1989). After the exploratory work of Zieher the efforts of recent years have concentrated on the numerical simulation (Westermann 1988; 1988a; 1988b), the development of detailed diagnostic tools (Rogner & Schultheiss 1986; Kühn & Rogner 1985; Klumpp & Bluhm 1986) and the focusing properties of the Bθ-diode (Citron et al. 1986; Bauer et al. 1987; Schimassek et al. 1988; Westermann 1988c). Experiments and numerical simulations on three modifications of the diode will be reported (version I, II, III).