An ultrasound transducer includes a substrate and a lower electrode layer, a lower insulating layer, an upper insulating layer, and an upper electrode layer laminated in order on the substrate. The lower insulating layer and the upper insulating layer are arranged to be opposed to each other via an air gap section. The upper insulating layer and the lower insulating layer are different in a material and thickness and satisfy Equation 1 below. In Equation 1, K1 represents a relative dielectric constant of the lower insulating layer, K2 represents a relative dielectric constant of the upper insulating layer, T1 represents layer thickness of the lower insulating layer, T2 represents layer thickness of the upper insulating layer, ρ1(x) represents a charge density distribution in the lower insulating layer (x represents a distance from the lower electrode layer), and ρ2(y) represents a charge density distribution in the upper insulating layer (y represents a distance from the upper electrode layer).
