The present invention provides a compound, an oxepin derivative having excellent histamine receptor antagonistic action, which is useful as an antihistamine. The oxepin derivative of the present invention has a potent histamine receptor antagonistic action. Further, the compound of the present invention shows low intracerebral migration even when a mouse that is orally administered with the compound is subjected to an intracerebral receptor binding test, so that the compound has preferred properties of alleviating side effects in the central nervous system, such as drowsiness. The oxepin derivative of the present invention is very useful as a novel antihistamine having smaller side effects in the central nervous system, such as drowsiness.