The beautiful and sometimes poignant images were taken by the local photographer Frederick William Guerin, who was born on 6 June 1878. Many were used as picture postcards sold on the High Street in St Peter Port at Guerin's Picture Postcard Rooms.
His original glass negatives have been specially scanned for the exhibition, revealing island life from 1901 to 1910 in superb detail.
'John Fitzgerald specially scanned Guerin's original glass negatives, which are in the museum collection, and produced the prints for the exhibition which capture an amazing amount of detail. He has also made the prints available to buy through the museum website,' said registrar Lisa Burton.
From the coronation celebrations for Edward VII, the White Rock busy with produce for export and Mary Lucas at her fish market stall to shipwrecks, States divers and the Battle of Flowers, each photograph tells the story of Guernsey people, places and events before the outbreak of the First World War changed life forever.
The exhibition also includes vintage cameras, postcards and transport models, as well as an Edwardian dressing up area for children.
Other exhibits include 300 Years of English Freemasonry in the museum foyer and Evolution, the best art from the colleges and Grammar School, in the greenhouse gallery until September.
The Timewarp in the Discovery Room explores Ancient Egypt and the new Guernsey Folklore Gallery is now open.
An Unseen World: Photographs of Edwardian Guernsey by F W Guerin is at Guernsey Museum until 10 September 2017.
Admission: adults £6.50, children under 18 and students (with valid student card) £2. Children under seven, entry free of charge, but Discovery Pass holders and accompanying children are admitted free.