A toilet seat apparatus according to an embodiment is a toilet seat apparatus to be placed on an upper part of a toilet bowl, the toilet seat apparatus including: a toilet seat on which a user sits; a light emitting unit that emits light; and a light receiving unit that receives light; first memory that stores data received by the light receiving unit; and an arithmetic processing device that executes transfer of data received by the light receiving unit to the first memory, and analysis and deletion of data stored in the first memory, in which the arithmetic processing device transfers the data received by the light receiving unit to the first memory, and deletes the data temporarily stored in the first memory when the data has been analyzed to be data that is not data based on the reflected light from falling feces.