According to one embodiment, a toilet seat device includes a toilet seat, and a Doppler sensor using radio waves. An opened state of the toilet seat is sensed when approach of a user to the toilet seat is sensed based on a sensing signal outputted by the Doppler sensor. It is regarded that use is in progress for urination by the user when the toilet seat is in the opened state. In a state of being regarded that use is in progress for urination, a post-use operation is performed after sensing leaving of the user from the toilet seat based on the sensing signal.