The present invention provides a connector device having a structure in which a protruding or a recessed fitting portion is provided at a surface of a columnar terminal of a cable-side connector (first connector) and a recessed or a protruding fit portion is provided at a fixed contact piece of a U-shaped terminal of a substrate-side connector (second connector). In the connector device, when the connectors are connected to each other, the fitting portion that is provided at the surface of the terminal of the cable-side connector is fitted to the fit portion that is provided at the fixed contact piece of the terminal of the substrate-side connector, so that a force that prevents the connectors from coming off from each other (coming-off force) is increased.