Abstract: An openable and closeable screen door has a wire-netting screen that can be freely expanded and contracted and a mechanism to ensure that a handle bar moves smoothly without breaking the parallelism between its top and bottom end. The handle bar is attached to the leading end of the screen that can be pulled out from a screen case that constitutes one side of a doorframe. The handle bar is movable along upper and lower guide frames. The tail ends of a pair of strings are attached to the bottom end of the handle bar. The strings are extended and wrapped over deflectors disposed at the lower ends of the screen case handle bar stopper, deflectors disposed at their upper ends, and again over deflectors. The leading ends of the strings are fastened to the top end of the handle bar. All segments of the two strings thus extended run in the same direction, thereby markedly decreasing friction therebetween.