A safety device for the needle of intravenous catheter apparatus comprising of a tip blocker which blocks the needle tip, a spring assembled in compressed state held by a disc inside the groove of the tip blocker which pushes the tip blocker downwards and a bush fitted in the needle passageway which does not allow the needle to come out of the safety device. The safety device is capable of locking inside it and covering the needle tip so that the needle of intravenous catheter apparatus can be disposed of safely.