There are two aims of this paper. The first purpose is to explore major political outcomes brought about by slipsof the tongue of the ministers in Japan. The other is to attempt at their empirical demonstration. As far as we know,few earlier studies in political language have attempted an actual validation of alleged effects of political language. The present paper shows political functions, political effects and political responsibilities of slips of the tongue ofthe ministers in Japan. Three major political functions and effects are a point of attack against the Government par-ties by the oppositions, cause of a split in the diplomatic relations between Japan and the countries concerned, desta-bilization of the foundation of coalition government. These three political functions or influences can be found inmost cases of slips of the tongue of the ministers. This paper also clarifies the political responsibilities of the minis-ters concerned. The ministers in question have never been appointed to posts of minister or to important posts in theDiet or LDP once they resigned from the ministerial position because of the slip of the tongue. They have, however,never lost their positions as a member of the Diet. This is because slips of the tongue have little effect on the elec-tions of the ministers. Why do the opposition parties use these slips of the tongue as an object of attack against the Government parties?Support expansion and vote acquisition will be plausible answers. This paper attempts to show whether these twofunctions work or not. For this purpose, it discusses the result of a national election, especially the rates of votes andthe number of elected persons, of the House of Representatives. The result shows that the political functions of sup-port expansion and vote acquisition work hardly in the medium and small electoral districts. However, PrimeMinister Yoshiro Mori's verbal missteps have a considerable effect on the election of proportional representation.