A sample preparation device comprising: a filter member including a filter configured to separate cells being an analysis target from other components in a sample; a first receptacle and a second receptacle configured to be connected to each other via the filter; a third receptacle capable of holding the sample therein; a communication hole formed in the first receptacle and configured to allow the sample to go into and out of the first receptacle; a flow path configured to allow the third receptacle to be communicated with the communication hole; a negative pressure section configured to apply a negative pressure into the second receptacle, thereby to move the sample in the third receptacle toward the filter via the flow path and the first receptacle, and thereby to move components other than the analysis target into the second receptacle via the filter; a positive pressure section configured to apply a positive pressure from the second receptacle side to the filter, wherein the cells being the analysis target are attached to the filter in the first receptacle side; and a rotating member provided in the first receptacle and configured to rotate along a filtering face of the filter, wherein the filter member is provided with a cylindrical portion having a cylindrical inner side face, the filter is located at a position inwardly displaced from an edge of the cylindrical portion, and the rotating member includes: an inner circular portion capable of being inserted into the cylindrical portion, characterised in that the rotating member also includes a restraining portion formed around the inner circular portion and configured to restrain the inner circular portion from coming into contact with the filter. a filter member including a filter configured to separate cells being an analysis target from other components in a sample; a first receptacle and a second receptacle configured to be connected to each other via the filter; a third receptacle capable of holding the sample therein; a communication hole formed in the first receptacle and configured to allow the sample to go into and out of the first receptacle; a flow path configured to allow the third receptacle to be communicated with the communication hole; a negative pressure section configured to apply a negative pressure into the second receptacle, thereby to move the sample in the third receptacle toward the filter via the flow path and the first receptacle, and thereby to move components other than the analysis target into the second receptacle via the filter; a positive pressure section configured to apply a positive pressure from the second receptacle side to the filter, wherein the cells being the analysis target are attached to the filter in the first receptacle side; and a rotating member provided in the first receptacle and configured to rotate along a filtering face of the filter, wherein the filter member is provided with a cylindrical portion having a cylindrical inner side face, the filter is located at a position inwardly displaced from an edge of the cylindrical portion, and the rotating member includes: an inner circular portion capable of being inserted into the cylindrical portion, characterised in that the rotating member also includes a restraining portion formed around the inner circular portion and configured to restrain the inner circular portion from coming into contact with the filter.