Disclosed are a washing machine and a control method thereof, capable of preventing occurrence of an accident related to a child or a pet being inside a washing tub. A washing machine according to an aspect of the present disclosure includes a concentration sensing part configured to a sense a concentration of a specific component in air measured inside or outside the washing tub, a controller configured to switch the door and the washing tub to a safe mode based on the concentration of the specific component sensed by the concentration sensing part, and a release signal detector configured to detect a release signal for switching the door and the washing tub, which have been switched to the safe mode by the controller, back to a normal mode.