The first camera to feature automatic exposure was the selenium light meter-equipped, fully automatic Super Kodak Six-20 pack of 1938, but its extremely high price (for the time) of $225 ($ in present terms) kept it from achieving any degree of success.
The next technological advance came in 1960, when the German Mec 16 SB subminiature became the first camera to place the light meter behind the lens for more accurate metering.