A server casing using a sliding apparatus for easy insertion and removal of blade servers includes a chassis and the sliding apparatus. The chassis includes a blocking member. The sliding apparatus includes a first fastening plate, a second parallel fastening plate being mounted to the first fastening plate. A sliding plate is slidably connected to the second fastening plate. The sliding plate is received between first and second fastening plates and there is a locking member with first and second ends. The first end is rotatably connected to the second fastening plate and includes a locking portion, the second end is connected to the sliding plate. The locking portion can move between a locking position, where the locking member is locked by the blocking member, and an unlocking position, where the locking member is unlocked by the blocking member.