Abstract: A vertical drainage device including a generally plate-like elongated conduit member formed of a synthetic resin and a non-woven fabric attached to the conduit member. The vertical drainage device is adapted to be embedded into soil in a vertical direction coincident with a longitudinal direction of the conduit member and adapted to suck up water existing in the soil. The conduit member is comprised of a plurality of parallel vertical ribs extending in the longitudinal direction of the conduit member and a plurality of transverse ribs extending in a transverse direction of the conduit member for connecting the vertical ribs together. A spacing 1 between the adjacent ones of the vertical ribs is set to a 0.5 mm-5 mm, so as to define a conduit space between the adjacent vertical ribs. Accordingly, a drainage efficiency of the vertical drainage device can be greatly improved.