One aspect of the present invention provides a nucleic acid extraction device. The nucleic acid extraction device includes a container which stores each of a cleaning solution and an eluting solution, a water level sensor configured to detect amounts of the cleaning solution and the eluting solution which are stored in the container, a tube sensor configured to sense a sample tube disposed on a sample tube accommodation portion, and an operation initiation portion configured to determine whether the cleaning solution and the eluting solution which are necessary for a nucleic acid extraction operation are provided on the basis of the number of such sample tubes which is sensed by the tube sensor and the amounts of the cleaning solution and the eluting solution which are sensed by the water level sensor.