PURPOSE: To use a beautiful filling type face cover by forming only one drainage passage of a slit width that is smaller than the width of lid receiving shoulders and of a substantially L longitudinal cross section and can make flowing water of a maximum rainfall on a road surface flow in the fitted and borne portion of the lid of a side drain.

CONSTITUTION: Spacer bases 6 for forming drainage passages 10 are fixed to bearing positions at both ends of a lid on lid receiving shoulders 4 and 5 of a side drain. When the drain lid 11 is fitted and borne on the lid receiving shoulders 4 and 5 through the spacer bases 6, slit drainage passages 10 with width (c) and (d) and of a substantially L longitudinal cross section, that is smaller than the width of the lid receiving shoulders 4 and 5 are formed and makes flowing water of a maximum rainfall flow on lidded both sides. Flowing water from a road surface 7 is made to flow and drained into the side drain 1 by using only those passages 10, thereby using a non-porous, beautiful filling type face lid matched with a finishing material such as face tiles on the road surface side.