To provide a device by which pressurized washing liquid can be effec tively, continuously jetted without increasing pollutant sources.

In the pressurized washing liquid jetting device provided with a pressurized liquid source 1 for washing liquid, a liquid sending line 2 connected to the pressurized liquid source, an ejector 16 installed at the head of the liquid sending line, and an intensifier 3 connected in mid-way of the liquid sending line and for enabling increasing liquid pressure in tube by action of a pneumatic piston 4. After the liquid sending line 2 is branched into two directions away from the pressurized liquid source 1, the branches are joined and the joined line leads to the ejector 16, and also the intensifier 3 is of a double acting type in which liquid pressurizing pistons 7a, 7b are connected to the pneumatic piston 4 on both sides thereof through piston rods 5a, 5b. To one and the other of the liquid sending branches, one and the other head chambers 6a, 6b of the liquid pressure piston are connected respectively.