a diagonal elevation apparatus comprises a frame fitted to a sloped surface connecting the floor surface of a lower floor to the floor surface of an upper floor , a platform and a counterweight . the platform is disposed inside the frame and has first guide rollers guided by first guide rails , and a platform gate on a step surface . the counter - weight is equipped with second guide rollers and has second guide rails for the second guide rollers . the second guide rails are disposed inside the first guide rails . the platform and the counter - weight are connected to each other by divided plain belts through pulleys disposed at the upper and lower ends of the frame at the front and back of the platform and the counter - weight . the diagonal elevation apparatus further comprises means for moving the platform , comprising a linear motor fixed inside the frame and a brake device , or a variable speed motor equipped with a reduction gear .