A hand tool articulating apparatus has a pair of elongate members coupled for articulation about a pivot axis. The on-state characteristics of the transistor are improved as follows: an end portion of a source electrode and an end portion of a drain electrode overlap with end portions of a gate electrode, and the gate electrode surely overlaps with a region serving as a channel formation region of an oxide semiconductor layer. The ladder frame is coupled to the base and is rotatable about an edge axis.