There are here disclosed an electron-emitting device, comprising a pair of conductors arranged on a substrate so as to face each other, and a pair of deposited films containing carbon as a main component which are connected to the pair of conductors respectively and which ate arranged putting a gap therebetween, wherein silver is contained in a ratio of 5 mol % to 10 mol % with respect to carbon in the deposited film, an electron source comprising the plurality of electron-emitting devices arranged on a substrate and a wire connected to the electron-emitting devices and an image-forming apparatus comprising the electron source and an image-forming member which performs image formation by the collision of electrons emitted from the electron source.