A focal plane shutter has a base plate provided with a shutter opening, opening and closing sector groups each having a plurality of sectors, and a plurality of arms each having one end pivotally supported on the base plate so as to pivotally connect and support the sectors through connecting pins to form a parallel link mechanism. Each of the connecting pins has a tapered portion or a flange having a diameter small enough to prevent the action of each sector from being hindered when any of the sectors becomes interposed between any of the remaining sectors or an arm supporting the sector and any of the other sectors. Each of the arms may also have a reduced thickness portion proximate the connecting pin corresponding thereto to thereby prevent movement of the interposed sector from being hindered.