A sterilization process test device for verifying the efficacy of a sterilization process includes a tubular body defining a chamber for containing at least one sterilization indicator and a cap to sealingly close the tubular body. The tubular body includes at least one hole, which is covered by a gas and steam permeable cover. The only flow path into the chamber is provided through the steam and gas permeable cover and the at least one hole, which when combined are configured to control and restrict a flow of steam or a gaseous sterilization medium from an external environment.