A three-dimensional printing apparatus includes a base including an opening, a tank placed on the base and storing a liquid photo-curable resin, an optical device including a light source that emits light and arranged to irradiate the resin inside the tank with light emitted from the light source through the opening, a shutter that covers the opening in an openable and closable manner, a slide guide that guides sliding of the tank so that the tank is slidable between a preparation position located outside of a region over the opening and an installation position located over the opening, and an interlocking device that opens and closes the shutter in conjunction with sliding of the tank so that the shutter is opened when the tank is located over the entire opening, and the shutter is closed when the tank is not located over at least a portion of the opening.