A stage apparatus includes a Y-direction deformable body including a stationary support member, a movable support member and a pair of X-direction leaf springs to form a substantially rectangular shape in a free state; and an X-direction deformable body, positioned in the Y-direction deformable body, including a connecting member, a support member and a pair of Y-direction leaf springs to form a substantially rectangular shape in a free state. The support member of the X-direction deformable body includes a support member joint portion which joins the support member to the movable support member of the Y-direction deformable body. The X-direction deformable body and the Y-direction deformable body are integrally molded by synthetic resin together with the support member joint portion.