Disclosed herein are a washing machine and a control method thereof. The control method includes sensing a first unbalance amount of a drum in which laundry is received while rotating the drum at a first rotational velocity, sensing a second unbalance amount of the drum while accelerating the drum to a second rotational velocity, when the first unbalance amount is allowed, and accelerating the drum to a target rotational velocity, when the second unbalance amount is allowed.