An insulating glazing unit having a first pane, a second pane, an outer pane interspace, an inner pane interspace, and a spacer is described. The spacer has a glazing interior surface, a first pane contact surface, and a second pane contact surface, a plastic profile, a primary sealing means, and a main member. The main member contains a sealing material containing a drying material. The plastic profile separates the outer pane interspace from the inner pane interspace. The main member is arranged in the outer pane interspace adjacent the plastic profile and the primary sealing means is arranged in the outer pane interspace adjacent the main member.