In accordance with one embodiment of the present invention, there is disclosed an apparatus for nucleic acid extraction and an operation method thereof. The apparatus for nucleic acid extraction includes: a first rack having a plurality of sample tube receivers arranged in a circle; a second rack having a plurality of elution tube receivers arranged in a circle on an outer side thereof and a washing solution receiver positioned at the center thereof, a part of the washing solution receiver extending outwards to have projections formed in alternation with a plurality of the elution tube receivers; a main body having the first and second racks arranged to position the first rack on the top of the second rack; a rotational driver for separately rotating the first and second racks; a dispenser for separately dispensing a washing solution and an eluting solution into sample tubes; and a pressurizer for maintaining the inside of the sample tubes under raised pressure.