A thin plate-shaped substrate 21 comprised of a monocrystal is provided with a piezoelectric element 24, and both ends of a movable piece 20 whose one surface is provided with a movable contact 25 are fixed and supported to a base 11. Then, by curving the movable piece 20 via the piezoelectric element 24, the movable contact 25 is brought in and out of contact with a pair of fixed contacts 38 and 39 that face the movable contact. With this arrangement, a subminiature micro-relay having a mechanical contact mechanism that has a small resistance in turning on the contact and the desired vibration resistance, frequency characteristic and insulating property can be obtained.