A method for controlling the concentration of a gas in a crisper drawer (100): by capturing the concentration of a freshness-preserving gas in a storage chamber (10) and comparing with a preset threshold, determining whether to feed the freshness-preserving gas into the storage chamber (10), or employing a timed feeding method to control whether to feed the freshness-preserving gas into the storage chamber (10). The method selectively feeds the fresh-preserving gas into the storage chamber (10), thus controlling the concentration of the freshness-preserving gas in the storage chamber (10) to be kept above a target concentration, significantly extending the time during which food is kept fresh, and at the same time, taking into consideration the economy of using the freshness-preserving gas.
