An image forming apparatus comprising: a cover openably/closably attached to an apparatus main body; and a locking mechanism configured to restrict a turning of the cover from a closed position, characterized in that the locking mechanism has: a first locking member and a second locking member movable between a lock position where they engage with the apparatus main body to restrict the turning of the cover from the closed position and an unlock position where they disengage with the apparatus main body to permit the turning of the cover; and a lever member configured to move the first locking member and the second locking member between the lock position and the unlock position, and the first locking member and the second locking member are formed so that an engagement quantity of the first locking member with the apparatus main body is longer than an engagement quantity of the second locking member with the apparatus main body at the lock position, and the first locking member is formed with an engaging piece which is turnable by turning of the cover in an opening direction at the unlock position, wherein if a depression of the lever member is pushed down, the first locking member and the second locking member are biased by a respective biasing member of the locking mechanism and slide into the unlock position, the first locking member, the second locking member and the lever member are supported by a respective hollow (35, 36, 37) provided at the cover, and the apparatus is further adapted such that the lever member slides in upward and downward directions to move the first locking member and the second locking member between the lock position and the unlock position in a direction opposite to each other in leftward and rightward directions. a cover openably/closably attached to an apparatus main body; and a locking mechanism configured to restrict a turning of the cover from a closed position, characterized in that the locking mechanism has: a first locking member and a second locking member movable between a lock position where they engage with the apparatus main body to restrict the turning of the cover from the closed position and an unlock position where they disengage with the apparatus main body to permit the turning of the cover; and a lever member configured to move the first locking member and the second locking member between the lock position and the unlock position, and the first locking member and the second locking member are formed so that an engagement quantity of the first locking member with the apparatus main body is longer than an engagement quantity of the second locking member with the apparatus main body at the lock position, and the first locking member is formed with an engaging piece which is turnable by turning of the cover in an opening direction at the unlock position, a first locking member and a second locking member movable between a lock position where they engage with the apparatus main body to restrict the turning of the cover from the closed position and an unlock position where they disengage with the apparatus main body to permit the turning of the cover; and a lever member configured to move the first locking member and the second locking member between the lock position and the unlock position, and the first locking member and the second locking member are formed so that an engagement quantity of the first locking member with the apparatus main body is longer than an engagement quantity of the second locking member with the apparatus main body at the lock position, and the first locking member is formed with an engaging piece which is turnable by turning of the cover in an opening direction at the unlock position, wherein if a depression of the lever member is pushed down, the first locking member and the second locking member are biased by a respective biasing member of the locking mechanism and slide into the unlock position, the first locking member, the second locking member and the lever member are supported by a respective hollow (35, 36, 37) provided at the cover, and the apparatus is further adapted such that the lever member slides in upward and downward directions to move the first locking member and the second locking member between the lock position and the unlock position in a direction opposite to each other in leftward and rightward directions.