A first deformation portion 53 is deformed by the external stress is continuously provided to the flat portion 52a of the cylindrical portion 52 disposed to surround the periphery of the switch unit 41, and is provided continuously to the curved portion 52b of the cylindrical portion 52 a second deformable portion 54 is deformed by an external stress, first, when the external stress is provided continuously to the second deformation portion 53, 54 of the first deformation portion 53 is deformed inwardly of the tubular portion 52 operation The stress of the vertical component with respect to the outer surface of the body section 23 to have the stress transmission portion 55 to transmit to the switch unit 41, a configuring the switch cover 50.スイッチ部41の周囲を囲繞して配設された筒状部52の平面部52aに連設され外部応力によって変形する第1の変形部53と、筒状部52の曲面部52bに連設され外部応力によって変形する第2の変形部54と、第1,第2の変形部53,54に連設され外部応力によって第1の変形部53が筒状部52の内側に変形されたとき操作部本体23の外面に対して垂直方向の成分を有する応力をスイッチ部41に伝達する応力伝達部55と、を有してスイッチカバー50を構成する。
