A vibration isolator comprising: a first attachment member to be attached to one of a vibration generating unit or a vibration receiving unit; a second attachment member to be attached to another of the vibration generating unit or the vibration receiving unit; an elastic member that is provided at the second attachment member and elastically connects the first attachment member and the second attachment member ; convex portions , each protruded toward the first attachment member with reference to an outer surface of the elastic member opposed to the first attachment member ; and concave portions , each of which is recessed at a region of the outer surface positioned on a base end side of a respective convex portion , forms an extension portion at a side wall portion of the convex portion , and forms an opposed face opposed to the extension portion ; characterised in that : each concave portion is extended along at least two directions orthogonal to a protrusion direction of the respective convex portion so as to cover a circumference of the convex portion , and when input in a twisting direction (K) is applied to each of the convex portions , each convex portion is inclined in a direction corresponding to the twisting direction (K), then a respective wall surface (48C, 48D, 48E, 52C, 52D 52E) on a base end side of the convex portion , or the respective extension portion comes into contact with the opposed face formed of the respective concave portion . a first attachment member to be attached to one of a vibration generating unit or a vibration receiving unit; a second attachment member to be attached to another of the vibration generating unit or the vibration receiving unit; an elastic member that is provided at the second attachment member and elastically connects the first attachment member and the second attachment member ; convex portions , each protruded toward the first attachment member with reference to an outer surface of the elastic member opposed to the first attachment member ; and concave portions , each of which is recessed at a region of the outer surface positioned on a base end side of a respective convex portion , forms an extension portion at a side wall portion of the convex portion , and forms an opposed face opposed to the extension portion ; characterised in that : each concave portion is extended along at least two directions orthogonal to a protrusion direction of the respective convex portion so as to cover a circumference of the convex portion , and when input in a twisting direction (K) is applied to each of the convex portions , each convex portion is inclined in a direction corresponding to the twisting direction (K), then a respective wall surface (48C, 48D, 48E, 52C, 52D 52E) on a base end side of the convex portion , or the respective extension portion comes into contact with the opposed face formed of the respective concave portion . each concave portion is extended along at least two directions orthogonal to a protrusion direction of the respective convex portion so as to cover a circumference of the convex portion , and when input in a twisting direction (K) is applied to each of the convex portions , each convex portion is inclined in a direction corresponding to the twisting direction (K), then a respective wall surface (48C, 48D, 48E, 52C, 52D 52E) on a base end side of the convex portion , or the respective extension portion comes into contact with the opposed face formed of the respective concave portion . <EOS>