An optical deflector comprising: a mirror; a first rib formed at an outer circumference of said mirror; a first support frame (2, 2') surrounding said mirror; at least one first torsion bar (3-1, 3-2) arranged along a first axis of said mirror and coupled between said first support frame (2, 2') and said mirror; and a pair of first actuators (4-1, 4-2; 5-1, 5-2) arranged between said first support frame (2, 2') and said first torsion bar (3-1, 3-2), wherein a first recess opposing said first torsion bar (3-1, 3-2) is formed within said first rib, wherein said first recess has a width larger than a width (W 1) of said first torsion bar (3-1, 3-2), characterized in that said first recess has a length along the first axis of said mirror at a portion opposing said first torsion bar (3-1, 3-2) between an end of said first torsion bar (3-1, 3-2) and a side of said first rib which length is larger than a length of said first recess along the first axis of said mirror at an outer circumference of said first rib not opposing said first torsion bar (3-1, 3-2) between an end of said mirror and a side of said first rib; and said optical deflector further comprising: a second support frame surrounding said first support frame; a second rib (2'a) formed on said first support frame; at least one second torsion bar (12-1, 12-2) arranged along a second axis of said mirror perpendicular to said first axis and coupled between said second support frame and said first support frame: and a pair of second actuators (13-1, 13-2; 14-1, 14-2) arranged between said second support frame and said second torsion bar (12-1, 12-2), wherein a second recess (2'b-1, 2'c-1, 2'd-1, 2'e-1) opposing said first torsion bar (3-1, 3-2) is formed within said second rib (2'a), and a third recess (2'b-2, 2'c-2, 2'd-2, 2'e-2) opposing said second torsion bar (12-1, 12-2) is formed within said second rib (2'a). a mirror; a first rib formed at an outer circumference of said mirror; a first support frame (2, 2') surrounding said mirror; at least one first torsion bar (3-1, 3-2) arranged along a first axis of said mirror and coupled between said first support frame (2, 2') and said mirror; and a pair of first actuators (4-1, 4-2; 5-1, 5-2) arranged between said first support frame (2, 2') and said first torsion bar (3-1, 3-2), wherein a first recess opposing said first torsion bar (3-1, 3-2) is formed within said first rib, wherein said first recess has a width larger than a width (W 1) of said first torsion bar (3-1, 3-2), characterized in that said first recess has a length along the first axis of said mirror at a portion opposing said first torsion bar (3-1, 3-2) between an end of said first torsion bar (3-1, 3-2) and a side of said first rib which length is larger than a length of said first recess along the first axis of said mirror at an outer circumference of said first rib not opposing said first torsion bar (3-1, 3-2) between an end of said mirror and a side of said first rib; and said optical deflector further comprising: a second support frame surrounding said first support frame; a second rib (2'a) formed on said first support frame; at least one second torsion bar (12-1, 12-2) arranged along a second axis of said mirror perpendicular to said first axis and coupled between said second support frame and said first support frame: and a pair of second actuators (13-1, 13-2; 14-1, 14-2) arranged between said second support frame and said second torsion bar (12-1, 12-2), a second support frame surrounding said first support frame; a second rib (2'a) formed on said first support frame; at least one second torsion bar (12-1, 12-2) arranged along a second axis of said mirror perpendicular to said first axis and coupled between said second support frame and said first support frame: and a pair of second actuators (13-1, 13-2; 14-1, 14-2) arranged between said second support frame and said second torsion bar (12-1, 12-2), wherein a second recess (2'b-1, 2'c-1, 2'd-1, 2'e-1) opposing said first torsion bar (3-1, 3-2) is formed within said second rib (2'a), and a third recess (2'b-2, 2'c-2, 2'd-2, 2'e-2) opposing said second torsion bar (12-1, 12-2) is formed within said second rib (2'a).