A substrate tray for accommodating at least one ceramic substrate therein including: an accommodation part including a first opening part of which the upper side is open so that the ceramic substrate can be accommodated and withdrawn; and a support part formed on the circumference of the accommodation part so as to support the side wall circumference of the ceramic substrate, wherein the support part includes: an inner wall in contact with at least one surface of the ceramic substrate; an outer wall spaced a predetermined distance from the inner wall; an upper surface for connecting the inner wall to the outer wall; and a second opening part formed to be open in the direction opposite to the first opening part at a location facing the upper surface between the inner wall and the outer wall.