An actuator includes a tabular partition that partitions, for each beam located at a position that allows the beam to abut the actuator, a through-hole into which one of a pair of beams located at the other-end side and at the position that allows the beam to abut the actuator is inserted to prevent the beam from abutting the actuator, and a wider-width part including a wider-width surface which is disposed at one end of the partition corresponding to an upstream side of a flow of resin flowed to mold the partition when the actuator is molded by the resin containing a filler, and which has a wider width than a width of the one end of the partition.