PURPOSE: To obtain a machine for spreading paste on a wall paper wherein the thickness of a paste applied on the back surface of a wall decorative material can be made to be approximately uniform.

CONSTITUTION: In this machine for spreading paste on a wall paper wherein a sheet-like wall decorative material is pulled into the inside from the rear part of the main body part by means of a plurality of rolls arranged in the main body and is moved along a specified path in the main body and a paste in a paste tub 6 arranged in the main body is applied continuously on the back surface of the wall decorative material, among a plurality of rolls, the outer shape of a doctor roll 30 (31) for adjusting the thickness of the paste applied on the back surface of the wall decorative material is made to be a crown shape wherein the central part in the shaft direction of the roll has a larger diameter than the both end parts of the roll.