There has existed a good deal of uncertainty, and indeed confusion. As to the effects of failure to observe rules of administrative procedure. In my opinion, the better view which can eliminate such uncertainty and confusion could be developed through taking the methodologies. The first methodology to be taken is differentiating a wide variety of admini-strative procedures, and failures to observe those procedures. The legal effects of failure to observe administrative procedure may make a wide range of spectrum from simply valid to absolutely void according to this typology. For example, the failure to observe a hearing procedure would make the referred ``administrative act`` revocable without any other substantive fault. The reason is that hearing procedures are very important to protect and represent the interests of relevant people. However, only a short notice without any other significant effect on the decision-making process of the referred ``administrative act`` would give no legal impact on the ``administrative act``. It might be uneconomical to make an ``administrative act`` revocable on the basis of only an ineffective little procedural fault. The second one is introducing the concept of ``procedural rights`` to this argument. If a procedural failure encroaches on someone`s procedural rights, then it would make the referred ``administrative act`` revocable without any other substantive fault. If not, it would not give any impact on the referred ``administrative act``. In my opinion, the concept of ``procedural rights`` bears independent values of administrative procedure such as transparency, clearness and democracy. These values must be protected independently from the relevant substantive rights.