An optical apparatus including an electrical component which is movable in a plane, and a flexible printed wiring board in the shape of a strip, the widthwise direction thereof being parallel to the plane, which connects the electrical component to a stationary board, wherein the flexible printed wiring board includes a folded extension portion which firstly extends in a direction substantially orthogonal to the plane and is subsequently folded back at a folded portion to extend in a direction opposite thereto; and at least one slit which is provided to pass through the folded portion and to split at least a part of the folded extension portion into at least two split portions thereof in the widthwise direction of the flexible printed wiring board.