Abstract: An adjustable wrench includes a fixed jaw, a movable jaw slidably disposed in the fixed jaw, a movable member disposed in the fixed jaw for driving the movable jaw to move, a handle pivoted on the fixed jaw for being pivoted back and forth relative to the fixed jaw, a stop pin and a switch post. The stop pin and the switch post are disposed on the handle, which allows the stop pin to move to a first position where the stop pin keeps the movable member from moving along an axial direction and a second position where the stop pin allows the movable member to move along the axial direction. The switch post is provided to control the movement of the handle. The adjustable wrench has a very small maximum clamping opening angle for turning the handle away from the fixed jaw when reversely operating the adjustable wrench.