Grill shutter

Provided is a grill shutter (10) configured to selectively open and close an external air intake opening (3) formed in a front part of a vehicle body (1). The grill shutter includes: a frame (11) surrounding the external air intake opening; a plurality of blades (12) rotatably supported by the frame and driven to rotate between a closed position for closing the external air intake opening and an open position for revealing the external air intake opening; a drive unit (13) for rotationally driving the blades; and a power transmission mechanism (12L 1 , 12R 1 , 20, 22, 24) transmitting a drive force of the drive unit to the blades, the power transmission mechanism configured to cause the blades to start an opening movement one after another with a predetermined time lag between successive opening movements.