A liquid sensor may comprise a first electrode, a second electrode disposed inside the first electrode, and a partition wall comprising a surface defining a storage space with a first opposing surface of the first electrode and a second opposing surface of the second electrode. One of the first electrode, the second electrode and the partition wall may comprise a first communication opening communicating an inside of the storage space and an outside of the storage space and disposed at an upper portion of the storage space. One of the first electrode, the second electrode and the partition wall may comprise a second communication opening communicating the inside of the storage space and the outside of the storage space and disposed lower than the first communication opening. An opening direction of the first communication opening may be different from an opening direction of the second communication opening.