A door latch device which allows shared use of a connector for use in door latch devices equipped with standard electric components and a connector for use in door latch devices equipped with special electric components in addition to the standard electric components, thereby achieving an increase in the efficiency of the work of connecting to an external connector and a reduction in costs. A connector (32) of a standard switch plate (26) has a coupling hole (51) which penetrates, in the connecting direction of the external connector, a portion having no standard connecting terminals (304). The coupling hole (51) can be fitted with another switch plate (46) that allows the passage of electric current through electric components different than the standard electric components.