Disclosed is a nonwoven sheet for use in absorbent articles such as disposable diapers which is capable of reducing the range of surface diffusion of, and reducing re-adhesion to the skin of, highly viscous fluid excretion. The disclosed nonwoven sheet has mutually perpendicular longitudinal, transverse and thickness directions, and has in the aforementioned thickness direction a front surface and a back surface opposite thereof. Ridges and grooves are formed alternately so as to extend in parallel in the aforementioned longitudinal direction and so as to form repeated undulations in the aforementioned transverse direction. The nonwoven sheet has a bottom surface which, when the aforementioned nonwoven sheet is placed on a horizontal surface with the back surface (opposite of the front surface in contact with the skin of the wearer) down, is the surface that contacts the aforementioned horizontal surface. On the back surface of the aforementioned grooves are formed in the aforementioned longitudinal direction alternately areas where the height from the bottom surface is relatively high and parts corresponding to the bottom surface. Openings are formed at least in the areas where the height from the bottom surface is relatively high, and a space is provided below said openings.
