A roll or tilt responsive switch includes a housing formed from an electrically conductive material and having an inclined face formed on the bottom to gradually rise concentrically outwardly substantially from the center of the bottom, and a header fixed to the housing to close its open end and having a through-aperture in which a terminal pin is fixed in an insulated relation. A contact is fixed to an end of the terminal pin located inside the housing and has a plurality of feather portions each having a predetermined elasticity and disposed concentrically with the terminal pin. An inertia ball is enclosed in the housing to be located substantially at the center in the housing in a normal position of the switch in a stationary state. The inertia ball rolls when subjected to oscillations, so that the inertia ball slides on the feather portions of the contact except for distal ends of the feather portions such that the inertia ball electrically conducts between the contact and the housing and such that the feather portions are elastically deformed, thereby receiving a force pushing the inertia ball against the bottom of the housing.