According to an aspect of the present invention, a toilet device includes: a washing unit washing a surface of a bowl in a toilet bowl; a water supplying unit supplying washing water to the washing unit; a silicic acid polymerization inhibiting unit adding inhibitor for silicic acid polymerization to the washing water left on the surface of the bowl after the washing of the bowl, the inhibitor inhibiting polymerization of silicic acid component in the washing water left on the surface of the bowl; and a control portion executing a control starting an operation of the silicic acid polymerization inhibiting unit before the surface of the bowl is evaporated.