Dust collection unit and vacuum cleaner with the same

A dust collection unit comprising:

• a container formed in an empty cylindrical shape and filled with water to a predetermined height above a lower wall, the container having an inlet and an outlet formed in an upper wall;
• and
• a water flow pipe whose top is joined to the inlet and whose bottom is submerged in water in such a manner that the bottom of the water flow pipe is spaced apart from the lower wall,
• wherein the water flow pipe comprises:
• a first pipe having a first inner diameter and being joined to the inlet;
• a second pipe having a second inner diameter smaller than the first inner diameter and extending downwardly from the bottom of the first pipe;
• and
• a water channel formed in a body of the second pipe defining the second inner diameter in such a way as to fluidably communicate with the inside of the second pipe,
• wherein the second pipe and the water channel are located under the surface of the water, and the dust contained in the air introduced into the second pipe through the first pipe is collected by the water supplied through the water channel.