Ernen has a population () of . In 2008, 5.2% of the population were resident foreign nationals. Over the 10 years 1999–2009, the population changed at a rate of -8.3%. It has changed at a rate of 0% due to migration and at a rate of -7.1% due to births and deaths. Most of the population in 2000 spoke
German (367 or 95.3%) as their first language,
Serbo-Croatian is the second most common (5 or 1.3%) and
Dutch is the third (3 or 0.8%). There are 2 people who speak
French, 1 person who speaks
Italian. Of the population in the municipality, 207 or about 53.8% were born in Ernen and lived there in 2000. There were 97 or 25.2% who were born in the same canton, while 48 or 12.5% were born somewhere else in Switzerland, and 26 or 6.8% born outside of Switzerland. In 2000, there were 231 private households in the municipality, and an average of 2.3 persons per household. In 2000, 163 apartments (29.0% of the total) were permanently occupied, while 285 apartments (50.6%) were seasonally occupied and 115 apartments (20.4%) were empty. Colors= id:lightgrey value:gray(0.9) id:darkgrey value:gray(0.8) ImageSize = width:960 height:210 PlotArea = height:150 left:100 bottom:50 right:100 AlignBars = justify DateFormat = x.y Period = from:0 till:500 TimeAxis = orientation:vertical AlignBars = justify ScaleMajor = gridcolor:darkgrey increment:100 start:0 ScaleMinor = gridcolor:lightgrey increment:20 start:0 PlotData= color:yellowgreen width:40 mark:(line,white) align:center bar:1850 from:start till:414 text:"414" bar:1860 from:start till:492 text:"492" bar:1870 from:start till:434 text:"434" bar:1880 from:start till:456 text:"456" bar:1888 from:start till:417 text:"417" bar:1900 from:start till:355 text:"355" bar:1910 from:start till:334 text:"334" bar:1920 from:start till:308 text:"308" bar:1930 from:start till:311 text:"311" bar:1941 from:start till:319 text:"319" bar:1950 from:start till:299 text:"299" bar:1960 from:start till:344 text:"344" bar:1970 from:start till:330 text:"330" bar:1980 from:start till:317 text:"317" bar:1990 from:start till:390 text:"390" bar:2000 from:start till:385 text:"385" bar:2018 from:start till:492 text:"492" ==Heritage sites of national significance==