"It was a surprise of a high order," said the 39-year-old Bristol-born author, who now lives in Paris. "Just to be on the shortlist with people like that was enough."
Miller's novel, which has already been sold in more than 30 countries, traces the career of a gifted West Country surgeon, James Dyer, across the political and intellectual ferment of Europe in the mid-18th century. Dyer cannot feel pain, and his quest for a cure for his bizarre isolation from ordinary human joy and sorrow lies at the heart of a narrative that the Impac judges praised for its "cunning and deep" imagination.
The multi-national judging panel, which included the writers Andre Brink from South Africa, Alberto Manguel from Canada and Julia O'Faolain from Ireland, added that Miller had powerfully addressed "one of the major moral issues of our time - the clash between the constraints of compassion and the ruthless modern pursuit of efficiency".
Created in 1995, the award is sponsored by the Florida-based Impac management consultancy, or "productivity enhancement company", which lists as one of its services "increasing a company's profitability through the reduction of costs".
The competition is hosted by the City of Dublin, where the Irish Prime Minister, Bertie Ahern, will present the prize at a dinner on 12 June.
The Impac stands apart from other literary contests not only by virtue of its uniquely generous funding, but also for its broad remit. Translated novels as well as books written in English can be submitted for the award, which collects nominations from librarians in more than 50 countries.
Last year the prize went to the only translated novel on the shortlist, The Land of Green Plums by the Romanian-born writer Herta Muller.
Andrew Miller's triumphant debut will confirm the reputation of the University of East Anglia's one-year MA in creative writing as a seed-bed for success. Miller is a graduate of the course, on which he was taught by Professor Malcolm Bradbury and the novelist Rose Tremain. But he points out that his tutors "never pretended to have some kind of magic wand" and that publishers and agents treat most course alumni with their usual scepticism.
Last year Miller followed up Ingenious Pain with Casanova, a novel that dramatised the legendary lover's exploits in Georgian London. His immersion in the Enlightenment era looks likely to continue with his third book, Oxygen. It will deal, he said, with "what can be saved and who saves what - whether mistakes you make years before are ever rectifiable".
He has not yet had any time to make any mistakes in disposing of his enormous Irish windfall. His plans so far extend no further than a good party.
The Northern Irish poet Paul Muldoon will be elected unopposed to the often contentious post of Professor of Poetry at Oxford University. Muldoon, 47, will replace the poet and former Independent journalist James Fenton in the 300-year-old position.
A campaign in support of the inventive and prolific Muldoon, who now teaches at Princeton University in the United States, has been masterminded by the poet, critic and Oxford don Tom Paulin. The five-year professorship is voted on by an electorate of Oxford MAs, although only a tiny fraction of eligible graduates ever votes. The job carries a light burden of lecturing duties, but has a record of inspiring memorable criticism. It has been won in the past by major figures such as W H Auden and Seamus Heaney.
'Ingenious Pain' is published by Sceptre (pounds 6.99).Reuse content