Abstract: An optical element holder having a simple structure and which is capable of being adjusted in six axes is disclosed. A movable plate is disposed among two pairs of side walls of a base, and a rotary plate for holding an optical element is integrally and rotatably held in the movable plate. The movable plate is adjusted by adjusting springs attached to one pair of side walls of the two pairs of side walls, and by adjusting screws attached to the other pair of side walls of the two pairs of side walls. The movable plate is moved along the base for adjustment with respect to the X and Y directions. The rotary plate is pushed by a coiled spring, which is rotated for adjustment with respect to the .theta. direction by an adjustment screw attached to the rotary plate. The movable plate and the rotary plate are integrally pushed toward the base by a plate spring, and by four adjustment screws attached to the rotary plate.