A substrate support includes a base, a support portion, a first pin member, a second pin member and a driving unit. The base has a first surface on which an object to be supported is placed, a second surface opposite to the first surface, and a first through-hole. The support portion has a third surface in contact with the second surface, a fourth surface opposite to the third surface, and a second through-hole. The first pin member is stored in the first through-hole and a second pin member is stored in the second through-hole. The first through-hole is larger on the second surface side than on the first surface side, and/or the second through-hole is larger on the third surface side than on the fourth surface side.