Provided is a particle separation apparatus. The particle separation apparatus for separating soil by particle size in a wet-type separation manner includes a body unit providing a space in which a mixture of the soil and water is received to flow vertically, a screen unit coupled to the inside of the body unit to separate the soil by the particle size from the mixture that flows vertically, and a space adjustment unit coupled to a lower portion of the body unit to cover the lower portion of the body unit, the space adjustment unit adjusting a volume of a lower space of the body unit to allow the mixture to repeatedly flow in a vertical direction.