IgE binding epitopes on allergens which induce allergic symptoms following surface contact, such as those associated with latex rubber and cat allergies, among others, can be blocked. A wallet created in accordance with the present invention comprises a database having various user data stored therein under certain predetermined field names. In the transistor, a buffer layer having n-type conductivity is formed between the source electrode layer and the oxide semiconductor layer and between the drain electrode layer and the oxide semiconductor layer.