Abstract: A stand includes a frame, a drive, and a moving support member; the frame has two opposing walls, and a base on a bottom thereof, which has two opposing upright parts; the drive includes a driving unit joined to the upright parts of the base, a driven shaft passed through the upright parts and pivoted on the opposing walls, chain wheels on two ends of the driven shaft, and two loop-shaped motion units passed over and engaged with respective ones of the chain wheels; the moving support member is joined to the loop-shaped motion units at two ends thereof by means of a coupling structure so as to be adjusted in height by means of operating the drive; L-shaped sliding pieces are secured on corners of the moving support member and propped against frame wall portions, which are joined to edges of said opposing walls of the frame.