To easily perform the replacing work of a blade while enhancing the attaching strength of the replaced blade in width and length directions.

A recessed groove 4 permitting the blade 2 to insert so as to leave the leading end part thereof is formed in a handle 1 in the length direction of the handle and the blade 2 inserted in the recessed groove 4 in a replaceable manner is fixed in a freely releasable manner by a fixing instrument 3 pressing the blade 2 in a thickness direction thereof. In the chisel thus constituted, the opposed side walls 5 and 5 of the recessed groove 4 are inclined so as to approach each other as the depth of the groove becomes deep.