A rotary anode unit includes a target formed of a first metal material and a target support body formed of a second metal material, formed in a flat plate shape, and having first and second surfaces. A thermal conductivity of the second metal material is higher than a thermal conductivity of the first metal material. A first recessed portion is formed in the first surface at the outer part of the target support body. The target is disposed in the first recessed portion. A second recessed portion configured to define a flow path for allowing a coolant to flow is formed in the second surface at the inner part of the target support body. A thickness of a first region where the first recessed portion is formed is larger than a thickness of a second region where the second recessed portion is formed.