Synthetic haggite V4O6(OH)(4) has been successfully obtained for the first time after a delay of more than 50 years. Our careful analysis clarifies the formula of haggite as V4O6(OH)(4), rather than the long-standing known V4O4(OH)(6). The semiconductor of haggite shows a rapid increase of resistance by >10(4) orders of magnitude down to low temperatures, giving the first case of the oxyhydroxide compound showing semiconductor-insulator transitions. More intriguingly, the haggite product's nanobelt that can act as connecting units have potential in the construction of intelligent switching devices in future investigations.