To provide a substrate treatment unit that suppresses gas intake and absorbs liquid efficiently from a substrate surface.

A suction nozzle 31 has an upper edge 32 and a lower edge 33 which have been opposed vertically along the moving direction X while inclining to a normal on a substrate surface WS. A suction route 34 is formed between these edges 32, 33 and processing solvents adhered to the substrate surface WS from one end 34a of the corresponding suction route 34 are absorbed and removed while carrying a substrate W. The end 34a of the suction route 34 is covered from the top with the extended area 321b of the upper edge 32 longer than the length of the lower edge 33 in the X direction, and its space SP extending below the extended area 321b is filled with processing solvents.