Provided is a continuous annealing line capable of producing a steel sheet excellent in hydrogen embrittlement resistance. A continuous annealing line 100 includes: a payoff reel 10 to feed a cold-rolled steel sheet S; an annealing furnace 20 to continuously anneal the cold-rolled steel sheet S and including a heating zone 22, a soaking zone 24, and a cooling zone 26; a downstream line 30; a tension reel 50 configured to coil the cold-rolled steel sheet S; and a vibration application device 60 or 70 configured to apply vibration to the cold-rolled steel sheet S being passed from the cooling zone 26 to the tension reel 50 so that the cold-rolled steel sheet is caused to vibrate at a frequency of 100 Hz or more and 100,000 Hz or less and a maximum amplitude of 10 nm or more and 500 μm or less.