According to one embodiment, an electrostatic chuck includes a ceramic dielectric substrate, a base plate, and a first electrode layer. The ceramic dielectric substrate has a first major surface and a second major surface. The first electrode layer is provided inside the ceramic dielectric substrate and connected to a high frequency power supply. The first electrode layer is provided between the first major surface and the second major surface. The first electrode layer has a first surface and a second surface. The first electrode layer includes a first region including the first surface, a second region including the second surface, and a third region positioned between the first region and the second region. A porosity of the first region is lower than a porosity of the third region.