Abstract: A magnetostrictive member is formed of a crystal of an iron-based alloy having magnetostrictive characteristics and is a plate-like body having a long-side direction and a short-side direction. At least one of a front face and a back face of the plate-like body has a plurality of grooves extending in the long-side direction.

Abstract: An electromagnetic switch is provided which comprises a movable switching contact movably supported by a movable switching contact assembly arranged on a support plate, a fixed switching contact, a magnetic coil assembly operable to urge the movable switching contact into contact with the fixed switching contact, and a retainer for retaining the fixed switching contact apart from the movable switching contact at a preselected interval. The retainer includes a switching contact mounting portion, a supporting portion secured to the support plate, and first and second connecting portions connecting the switching contact mounting portion and the supporting portion to form a polygonal frame structure which is so constructed as to be deformed under preselected forces applied thereto to adjust the positional relation between the movable and fixed switching contacts.