To provide a micro-relay with warp reduced in a direction of an oscillating axis of an armature part caused by coupling of a reinforcing member with an armature.

Coupling holes 39 are set in penetration at an armature part 30 of an armature block 3 along a direction of an axis (an oscillating axis X) at which the armature part 30 oscillates against a body 1, and at the same time, a reinforcing member 5 is provided jointing to an armature 32 through the coupling holes 39 for pinching the armature part 30 together with the armature 32. The reinforcing member 5 includes narrowed parts 5a narrower than other parts at sites opposed to the coupling holes 39. The narrowed parts 5a are of the same dimension in a direction crossing the oscillating axis X as that of the coupling holes 39, so that a contact area of the armature part 30 and the reinforcing member 5 is reduced to alleviate warp caused by coupling of the reinforcing member 5 with the armature 32.