PURPOSE: To facilitate the fine adjustment of extrusion nozzle position in coating a liquid, by communicating the interior of an extrusion nozzle with a compressed air supply device via the interior of the liquid storage and the hole of a block member.

CONSTITUTION: The piezoelectric element 1 is placed on a given position immediatley under the extrusion nozzle 34 with the sleeve 14 containing the conductive paste 8. Compressed air of a given pressure is supplied to the stepped through-hole 16 of the block member 11 by the control box 18 for a given time. Although the compressed air partly esapes from the chearance between the engaging part between the block member 11 and the sleeve 14, most of the air extrudes the paste 8 from the, sleeve 14. The working time of the air is controlled by a solenoid valve and a timer. When the three-way solenoid valve is turned off, the compressed air escapes quickly from the opening of the valve and the clearance between the block member 11 and the sleeve 14.