A bulk acoustic wave resonator is provided. The resonator includes a substrate; a resonant portion including a first electrode, a piezoelectric layer, and a second electrode sequentially stacked on the substrate; and a temperature compensation layer disposed at least one of above and below the piezoelectric layer, wherein a material of the temperature compensation layer has a coefficient of thermal expansion of which a sign is opposite to a sign of a coefficient of thermal expansion of a material of the piezoelectric layer, and wherein a relation of a thickness of the temperature compensation layer and a thickness of the piezoelectric layer satisfies the following equation: 0.25