A sanitary washing device according to an embodiment includes a toilet seat, a main part, and a radio wave sensor. The toilet seat is provided on a toilet. The toilet seat is pivotally supported by the main part. When the toilet seat is closed, the user in front of the main part is detected by the radio wave sensor in a first region, and in a second region higher than the first region. When the toilet seat is open, the user in front of the main part is not detected in the first region by the radio wave sensor, but the user in front of the main part is detected in the second region by the radio wave sensor. The position of the radio wave sensor is not changed between the state in which the toilet seat is open and the state in which the toilet seat is closed.