A flush toilet apparatus includes a hole wherein a tubular member is connected to a connecting portion disposed on the outside of a flush toilet apparatus through a hole portion formed at the rear top surface of a flush toilet main body, and the hole portion comprises a hole penetrating the entire wall thickness of the flush toilet main body; and an guiding path disposed adjacent to the hole, for guiding the tubular member to the hole; wherein at least a portion of the hole of the hole portion is covered by an affixing member, and the tubular member is inserted into the hole through the gap formed between the affixing member and the guiding path.