A storage case includes a front cover. An upper side of the front cover is rotatably connected to a top plate via a hinge structure. An outwardly protruding locking convex part is formed on the upper side of the front cover. In a first opened state where the front cover is turned upward about the upper side of the front cover as an axis, the locking convex part comes into contact with an engagement part on the top plate. When the front cover is turned upward from the first opened state and becomes in a second opened state in which the engagement part passes over the locking convex part, the locking convex part engages with the engagement part so that the front cover is locked in the second opened state. The locking convex part is recessed from a rear side of the front cover to be in a shell-shaped form.