<p>The present invention provides highly-stable oxide semiconductors which make it possible to provide devices having an excellent stability. The oxide semiconductor according to the present invention is an amorphous oxide semiconductor including at least one of indium (In), zinc (Zn), and Tin (Sn) and at least one of an alkaline metal or an alkaline earth metal having an ionic radius greater than that of gallium (Ga), and oxygen.</p>
