A substrate holder includes a first boat configured to hold a substrate in a shelf-like manner, and a second boat coaxial with the first boat and provided to move up and down relative to the first boat. The second boat holds a substrate in a shelf-like manner. The first boat includes a first bottom plate and a first ceiling plate provided to face each other, a first support column connecting the first bottom plate and the first ceiling plate to each other, and a first placement surface on which the substrate is placed. The second boat includes a second bottom plate and a second ceiling plate provided to vertically face each other, a second support column connecting the second bottom plate and the second ceiling plate, and a second placement surface on which the substrate is placed. The second ceiling plate overlaps the first ceiling plate in a plan view.