A fastening device for a cupboard door, which includes a catch member that is slidable within a carriage, the catch member and the carriage being biassed outwardly by means of springs. A restraining member is displaceable into and out of engagement with the carriage to restrain displacement thereof, and has a projection for restraining it in engagement with the carriage. Both the restraining member and the projection are externally operable. The fastening device also includes a locking means having a bolt slidable in a housing which defines a blocking pin, a tumbler plate having an annular recess and a auxiliary plate having an H-shaped aperture, in which recess and aperture the pin is received. The plates engage the bolt and prevent displacement thereof unless the plates themselves are displaced relative to the pin.