<p>The present invention relates to a knife having a blade integrated with a sheath. According to the present invention, the knife having a blade integrated with a sheath includes: a blade made by a back part and a blade part in the opposite side of the back part; and a handle joined to one end of the blade. A sheath is attached to the blade to be detached, wherein a rear side of the sheath is elastically actuated in a vertical direction around a front end.</p>
