Purgatory includes as its main themes Yeats’s feeling of crisis and anxiety as an Anglo-Irish who was alienated from the Irish society, his skeptical view of the modern Ireland which was seeking after materialism and his predilection for eugenic thought. In Purgatory, Yeats reveals those representative themes of his later writing using the conventions of Gothic: for instance, the supernatural modes such as the transgression of the ancestors, whose tragic result affects the present, the ruined house, wild landscape, and the ghosts, the theme of ‘life in death’ and ‘the death in life’, the opposition of nature and culture and the Freudian psychological characteristics such as ‘the return of the repressed’ and ‘the uncanny.’ This paper aims to analyse how Yeats borrows and modifies those traditional Gothic conventions to convey his themes in a more effective and impressive way and to finally argue that Yeats came to be skeptical about the heroic theme and its representation. Yeats places the old man as a narrator who speaks for his thoughts, but at the same time he puts him as an unreliable narrator and shows us his limitation. Here arises irony, through which Yeats reconsiders his heroic theme that he has insisted throughout his lifetime. Through the old man’s failure to save his mother from her repeated pain of purgatory and his consequent helplessness, Yeats reveals the anti-heroic theme.