Provided are a cleaning device and a cleaning method of a semiconductor manufacturing apparatus, capable of performing a cleaning process more effectively as compared to conventional cases and obtaining a high cleaning effect. A semiconductor manufacturing apparatus cleaning device 100 includes a pure water steam generating vessel 2 for generating pure water steam from pure water; a supply port 5for supplying the pure water steam to a cleaning target portion; a supply line 4 for connecting the pure water steam generating vessel with the supply port; a collection port 6 for collecting steam used in cleaning from the cleaning target portion; a collection vessel 8 for condensing and collecting the used steam; and a collection line 7 for connecting the collection port 6 with the collection vessel 8.