Abstract: A detachable screen protector assembly mounted on a screen frame of a monitor having a lower front surface and an upper front surface and has a screen protector and a fastening apparatus. The fastening apparatus has at least one couple of a bracket and a detachable hook. The bracket is mounted on the screen frame to hold the screen protector. The detachable hook corresponds to the bracket, is mounted the screen frame above the bracket and holds the screen protector. The detachable hook has a bracket member mounted on the upper front surface of the screen frame and a hooking member detachably mounted to the bracket member and holding the screen protector. Because the hooking member may disengage from the bracket member, the screen protector can be detached from the screen frame to be cleaned or be mounted on other monitors when people change their monitor.