A holding device manufacturing method includes a step of preparing a first joined body which includes a pre-machining ceramic member having a first surface and a fifth surface located opposite the first surface and approximately parallel to the first surface, a base member, and a joining portion disposed between the first surface of the pre-machining ceramic member and a third surface of the base member and joining the pre-machining ceramic member and the base member together. The thickness of the joining portion of the first joined body in a first direction, in which the first surface and the third surface face each other via the joining portion, increases from one end side toward the other end side of the joining portion in a second direction perpendicular to the first direction. The method includes a step of machining the fifth surface of the pre-machining ceramic member in the first joined body.