A particulate detection system (1) for detecting the quantity of particulates S in a gas under measurement EG, including a detection section (10), a drive circuit (210, 240), and a control section (230, 202). The detection section (10) has an ion source (11) and a particulate electrification section (12). The drive circuit (210) includes an ion source drive circuit (210) for performing constant current control. The control section (230, 202) includes current convergence determination means S2-S3, S5-S6, and detection start means S8 for starting detection of the quantity of the particulates S using the signal Is, detected by a detection circuit (230), after the gaseous discharge current Id has converged to an allowable range IR.