PURPOSE: To apply a constant amount of grease regardless of a residual amount by providing a float with a V-groove falling by the control of air pressure due to a syringe adaptor in a syringe.

CONSTITUTION: When the air controlled in pressure by a syringe adaptor 11 is sent into a syringe 12, a float 13 falls. The grease in the syringe 12 is extruded by the falling of the float 13 to be sent to a coating head 6 through a holder 14. At this time, since there is a packing 15 between the syringe 12 and the holder 14, the back flow of the grease due to pressure is prevented. By this method, a constant amount of the grease can be applied regardless of a residual amount and the coating head is small and an opening and closing mechanism can be dispensed with.