A detection system for detecting objects to be detected, the detection system comprising: a plurality of detection instruments (3a-3d), each detection instrument (3a-3d) comprising a detection instrument body and a cartridge (20A, 20B) that is to be exchangeably attached to a slot (SL1, SL2) included in the detection instrument body and that includes sensitive membranes sensitive to a substance, the detection instrument body being configured to generate first data representing reaction levels of the sensitive membranes associated with arrangement places of the sensitive membranes in the slot (SL1, SL2), each detection instrument (3a-3d) comprising second data representing membrane information for identifying the substances to which the sensitive membranes are sensitive, associated with the arrangement places of the sensitive membranes in the slot (SL1, SL2); and a substance detector that is configured to collect the first data and the second data from the detection instruments (3a-3d), is configured to generate, based on the collected first data and second data, reaction level data representing the reaction levels of the membranes associated with said membrane information of the sensitive membranes, comprises a database in which data groups in which the reaction level data and the objects to be detected are associated with each other are accumulated, is configured to accumulate, in the database, the data groups of known objects as the objects to be detected and the reaction data obtained by detection of the known objects, and is configured to, using the reaction level data obtained by detection of unknown objects as the objects to be detected, refer to the database to specify the unknown objects as the objects to be detected. a plurality of detection instruments (3a-3d), each detection instrument (3a-3d) comprising a detection instrument body and a cartridge (20A, 20B) that is to be exchangeably attached to a slot (SL1, SL2) included in the detection instrument body and that includes sensitive membranes sensitive to a substance, the detection instrument body being configured to generate first data representing reaction levels of the sensitive membranes associated with arrangement places of the sensitive membranes in the slot (SL1, SL2), each detection instrument (3a-3d) comprising second data representing membrane information for identifying the substances to which the sensitive membranes are sensitive, associated with the arrangement places of the sensitive membranes in the slot (SL1, SL2); and a substance detector that is configured to collect the first data and the second data from the detection instruments (3a-3d), is configured to generate, based on the collected first data and second data, reaction level data representing the reaction levels of the membranes associated with said membrane information of the sensitive membranes, comprises a database in which data groups in which the reaction level data and the objects to be detected are associated with each other are accumulated, is configured to accumulate, in the database, the data groups of known objects as the objects to be detected and the reaction data obtained by detection of the known objects, and is configured to, using the reaction level data obtained by detection of unknown objects as the objects to be detected, refer to the database to specify the unknown objects as the objects to be detected. is configured to collect the first data and the second data from the detection instruments (3a-3d), is configured to generate, based on the collected first data and second data, reaction level data representing the reaction levels of the membranes associated with said membrane information of the sensitive membranes, comprises a database in which data groups in which the reaction level data and the objects to be detected are associated with each other are accumulated, is configured to accumulate, in the database, the data groups of known objects as the objects to be detected and the reaction data obtained by detection of the known objects, and is configured to, using the reaction level data obtained by detection of unknown objects as the objects to be detected, refer to the database to specify the unknown objects as the objects to be detected.