The toilet apparatus includes a main part and a toilet seat. The main part includes a case cover covering a function part and is attached on a toilet bowl. The toilet seat is attached rotatably to the case cover, and shifts between a closed state and an open state. The case cover includes an extending portion. A height becomes low toward forward. The toilet seat includes a toilet seat main body and a heating part. The toilet seat main body includes a first portion and a second portion. The first portion is positioned in front of the case cover in the closed state. The second portion rises backward from the first portion in the closed state, and overlaps the extending portion. An upper end surface of the extending portion changes to lower a height toward forward and to lower a height toward a side.