To make favorable the tact surface and space surface of application/ inspection, to increase inspection accuracy and to smoothly make a change of the application direction without deteriorating paste application property in a paste applying device.

In a paste applying device for applying linear paste to a substrate 50 from an applying nozzle 10 while moving a XY table on which the substrate 50 is mounted, image pickup cameras 20A, 20B, 20C and 20D are arranged in the forward and the rear and the right and the left of the applying nozzle 10 above the XY table 60, and slit light sources 30A, 30B, 30C and 30D for irradiating slit light perpendicular to the linear paste with respect to an intersection point of optical axes of the image pickup cameras and the XY table 60 from the diagonal direction are arranged, and based on image data taken by the image pickup cameras, normal/defective condition of the paste application property is decided.