An installation box for electrical distribution applications, comprising a housing suitable to accommodate one or more electrical devices, a door connected to said housing, and a mechanism for opening/closing said door, said mechanism comprising: - a handle which is mounted on said door rotating about a rotation axis relative to the door itself; and - a first locking/unlocking device for locking/unlocking said door to/from said housing; characterized in that said first locking/unlocking device is mounted on said door and is operatively connected to said handle and is actuated by a rotation of the handle itself so as it disengages from an associated first anchoring portion of said housing and allows opening of said door, wherein said first locking/unlocking device is configured to translate along a direction substantially parallel with said rotation axis when actuated by the rotation of said handle and comprises a first shaped body suitable to operatively interact with said handle and first elastic means configured to contrast the movement of said first shaped body when the first locking device/unlocking device is actuated by the rotation of said handle so as to disengage from said first anchoring portion of the housing and in that said mechanism comprises a second locking/unlocking device which is also mounted on said door and operatively connected to and actuated by a rotation of said handle so as it disengages from an associated second anchoring portion of said housing and allows opening of said door, wherein said second locking/unlocking device is configured to translate along a direction substantially parallel with said rotation axis when actuated by the rotation of said handle and comprises a second shaped body suitable to operatively interact with said handle and second elastic means configured to contrast the movement of said second shaped body when the second locking/unlocking device is actuated by the rotation of said handle so as to disengage from the associated second anchoring portion of the housing, said first and second locking/unlocking devices (20, 200) being mounted on said door along said rotation axis with said handle in between. - a handle which is mounted on said door rotating about a rotation axis relative to the door itself; and - a first locking/unlocking device for locking/unlocking said door to/from said housing; characterized in that said first locking/unlocking device is mounted on said door and is operatively connected to said handle and is actuated by a rotation of the handle itself so as it disengages from an associated first anchoring portion of said housing and allows opening of said door, wherein said first locking/unlocking device is configured to translate along a direction substantially parallel with said rotation axis when actuated by the rotation of said handle and comprises a first shaped body suitable to operatively interact with said handle and first elastic means configured to contrast the movement of said first shaped body when the first locking device/unlocking device is actuated by the rotation of said handle so as to disengage from said first anchoring portion of the housing and in that said mechanism comprises a second locking/unlocking device which is also mounted on said door and operatively connected to and actuated by a rotation of said handle so as it disengages from an associated second anchoring portion of said housing and allows opening of said door, wherein said second locking/unlocking device is configured to translate along a direction substantially parallel with said rotation axis when actuated by the rotation of said handle and comprises a second shaped body suitable to operatively interact with said handle and second elastic means configured to contrast the movement of said second shaped body when the second locking/unlocking device is actuated by the rotation of said handle so as to disengage from the associated second anchoring portion of the housing, said first and second locking/unlocking devices (20, 200) being mounted on said door along said rotation axis with said handle in between.