Abstract: A sample preparation apparatus for preparing a sample to be used for detecting specimens such as microorganisms isolated on a filter so as to enumerate microorganisms in the sample has a turntable on which multiple sample bases are formed, a filter insertion unit, an extractant spray apparatus, a luminescent reagent spray apparatus and a filter removal unit, disposed in order along a periphery of the turntable in a direction of rotation of the turntable. By eliminating the need to move filters between processing operations as well as any special skill required in the spraying of the extractant and reagent, the sample preparation apparatus can provide accurate microorganism counts quickly and efficiently.