A multi-stage detector capable of accurately detecting an input operations in steps. Since the vertical lengths of a plurality of displacement press members (137) and (138) displaceably supported on an up-and-down operation member (131) and downwardly energized by a press biasing mechanism (139) are different from each other. When the up-and-down operation member (131) is displaced downward, a plurality of press-contact detection elements (135) and (136) are pressed in order by the displacement press members (137) and (138).