A focal-plane shutter has a first plate having a first opening, a second plate having a second opening, a shutter blade disposed between the first plate and the second plate, for opening and closing the first opening and the second opening, and a thin plate disposed at a side of the first plate facing the shutter blade and extending in such a direction that the shutter blade travel. A distance between an edge of the first opening and a center of the first opening is greater than that between an edge of the thin plate and the center of the first opening.