The present invention relates to an inspection port for maintenance of a drain pipe and, more specifically, to an inspection port for maintenance of a drain pipe, capable of inspecting or repairing a drain pipe by cutting a part of the drain pipe installed in a bridge or an elevated road, where inspection or repair is needed and conveniently connecting the cut drain pipe thereafter. The inspection port for maintenance of the drain pipe according to the present invention includes: a first connecting pipe (101) and a second connecting pipe (102) formed into a semi-cylinder including screw threads (103) on the outer surfaces of both ends and rubber ring seating holes (106) formed into a protrusion on the inner sides of both ends; rubber rings (105) inserted into the rubber ring seating holes (106); a cap (110) including internal pressing pieces (111) in an axial direction and making the internal pressing pieces (111) press the rubber rings (105) when the first connecting pipe (101) and the second connecting pipe (102) are screwed by the screw threads (103); and a watertight means keeping the joined surface of the first connecting pipe (101) and the second connecting pipe (102) watertight.
