Ratchet wrench

A ratchet wrench, comprising:

• a handle having a head portion at an end thereof, a through hole, a first chamber and a second chamber at said head portion, wherein said first chamber has opposite sides thereof communicated with said through hole and said second chamber respectively;
• a driving device having a polygonal hole at a center thereof and teeth at an outer surface thereof installed in said through hole of said handle for free rotation;
• a pawl having teeth at a side thereof and a driven portion at an opposite side thereof movably received in said first chamber to detachably mesh said teeth thereof with said teeth of said driving device;
• a switching device having an axle member and a turning member at an end of said axle member, wherein said axle member is received in said second chamber of said handle for free rotation and said turning member is left out of said handle;
• a supporting device, which is substantially a U-shaped element, having two substantially parallel extending segments and a contacting segment with opposite ends thereof connected with distal ends of said extending segments, wherein free proximal ends of said extending segments are movably connected with said axle member of said switching device and said contacting segment is received in said first chamber of said handle, and
• biasing means elastically urging said contacting segments of said supporting device against said pawl at said driven portion.