A tray and process for hydrogen peroxide vapor sterilization of medical articles. The tray includes a bottom surface and side walls defining a space to receive articles to be sterilized. The bottom surface of the tray includes a number of inlet passages and wells with a known volume. In the process of the present invention, articles to be sterilized are placed in the tray, and aqueous solutions of hydrogen peroxide is delivered into the tray. When the excess hydrogen peroxide is drained through the inlet passages, a known volume of peroxide remains in the wells. Such remaining hydrogen peroxide is then vaporized to achieve sterilization.