A nucleic acid extraction kit, which enables the nucleic acid extraction operation to be accomplished safely without causing contamination, and in which the complex preparation of reagents and the disposal treatments that are performed before and after the nucleic acid extraction operation can be performed rapidly and simply, with the extraction performed in an automated manner. The nucleic acid extraction kit includes: a container including reagent wells that each store at least a reagent, a sample well into which a biological sample is introduced, a waste liquid well, and a collection well in which an extracted nucleic acid is collected, and an extraction filter cartridge equipped with an extraction filter for separating and extracting a nucleic acid from the biological sample, wherein the extraction filter cartridge is formed in a manner that enables the extraction filter cartridge to be supported on the waste liquid well and the collection well.