A liquid crystal antenna includes a first substrate, a second substrate, and liquid crystals arranged between the first substrate and the second substrate. First protrusions and second protrusions are arranged at a surface of the second substrate facing the first substrate, a size of each first protrusion in a first direction is substantially greater than a size of each second protrusion in the first direction, and the first direction is a direction perpendicularly from the second substrate to the first substrate. A run-through labyrinth-type gap is defined by the first protrusions at a surface of the second substrate, and each second protrusion is arranged in the labyrinth-type gap.