A lens holder driving device comprising: a lens holder to which a lens barrel is attachable; a fixing part (12,30) disposed at an outer periphery of the lens holder; a driving mechanism (16,18,20) for driving the lens holder in a direction of an optical axis of a lens; an upper leaf spring configured to couple the lens holder and the fixing part (12,30) at an upper part thereof; and a lower leaf spring configured to couple the lens holder and the fixing part (12,30) at a lower part thereof, wherein: each of the upper leaf spring and the lower leaf spring includes an inner periphery side end part (222,242) fixed to the lens holder, an outer periphery side end part (224,244) fixed to the fixing part (12,30), and a plurality of arm parts provided along a circumferential direction for coupling between the inner periphery side end part (222,242) and the outer periphery side end part (224,244); the arm parts of the upper leaf spring and the arm parts of the lower leaf spring have substantially the same shape in a plan view; each of the arm parts (226,246) includes at least one U-turn-shaped portion (226a,246a) having a folded-back shape; at least one of the upper leaf spring and the lower leaf spring includes at least one stretchable and flexible resin provided as a bridge between opposite portions in the U-turn-shaped portion (226a,246a) of the arm parts (226,246); and the U-turn-shaped portion of the arm parts includes positioning protrusions at opposite portions of the u-shaped portion where the resin is applied, protrusions being configured to facilitate bridging of the resin with a surface tension of the resin at the opposite portions. a lens holder to which a lens barrel is attachable; a fixing part (12,30) disposed at an outer periphery of the lens holder; a driving mechanism (16,18,20) for driving the lens holder in a direction of an optical axis of a lens; an upper leaf spring configured to couple the lens holder and the fixing part (12,30) at an upper part thereof; and a lower leaf spring configured to couple the lens holder and the fixing part (12,30) at a lower part thereof, wherein: each of the upper leaf spring and the lower leaf spring includes an inner periphery side end part (222,242) fixed to the lens holder, an outer periphery side end part (224,244) fixed to the fixing part (12,30), and a plurality of arm parts provided along a circumferential direction for coupling between the inner periphery side end part (222,242) and the outer periphery side end part (224,244); the arm parts of the upper leaf spring and the arm parts of the lower leaf spring have substantially the same shape in a plan view; each of the arm parts (226,246) includes at least one U-turn-shaped portion (226a,246a) having a folded-back shape; at least one of the upper leaf spring and the lower leaf spring includes at least one stretchable and flexible resin provided as a bridge between opposite portions in the U-turn-shaped portion (226a,246a) of the arm parts (226,246); and the U-turn-shaped portion of the arm parts includes positioning protrusions at opposite portions of the u-shaped portion where the resin is applied, protrusions being configured to facilitate bridging of the resin with a surface tension of the resin at the opposite portions. each of the upper leaf spring and the lower leaf spring includes an inner periphery side end part (222,242) fixed to the lens holder, an outer periphery side end part (224,244) fixed to the fixing part (12,30), and a plurality of arm parts provided along a circumferential direction for coupling between the inner periphery side end part (222,242) and the outer periphery side end part (224,244); the arm parts of the upper leaf spring and the arm parts of the lower leaf spring have substantially the same shape in a plan view; each of the arm parts (226,246) includes at least one U-turn-shaped portion (226a,246a) having a folded-back shape; at least one of the upper leaf spring and the lower leaf spring includes at least one stretchable and flexible resin provided as a bridge between opposite portions in the U-turn-shaped portion (226a,246a) of the arm parts (226,246); and the U-turn-shaped portion of the arm parts includes positioning protrusions at opposite portions of the u-shaped portion where the resin is applied, protrusions being configured to facilitate bridging of the resin with a surface tension of the resin at the opposite portions.