A floor washing-drying machine includes a brush (2) adapted to scrub a floor (4) with a cleaning liquid in view of removing soil and dirt therefrom, and a wiping device (3) adapted to scrape the floor (4) in order to remove the dirty cleaning liquid therefrom. The wiping device (3) includes a front flap (5) and a rear flap (6) adapted to elastically and slidably engage the floor (4) so as to define a suction chamber (7) therebetween, with the suction chamber being fluidly connected with a suction device (8). A further elastic flap (10) is mounted to the wiping device behind the rear flap, and the width of the further flap is smaller than the width of the front and rear flaps (5, 6).