According to the prior art of a wrench holder disclosed in U.S. Pat. No. 5,346,063, it comprises a flat main frame which has two pieces of plates protruded from its both sides on the front. There is a plurality of recesses symmetrically defined on the two plates for wrenches to be placed. Each opening of the recess has a hook, and the wrenches are prevented falling from the recesses by the hooks. There are certain disadvantages from the prior art:
1. Wrenches are not able to be firmly held in the recesses with only two plates and simple-designed recesses on the main frame.
2. The holder can only be laid down due to the flat design of the main frame. Because the wrench holder is not standable, it causes inconvenient for users to choose proper wrenches.