Synchrotron-based research has moved from being a challenge within accelerator physics alone to becoming a versatile and widespread scientific tool. Today, a state-of-the-art light source attractsa broad range of scientific communities with the unique experiments that can be performed at synchrotron radiation sources. The MAX-laboratory in Lund has proposed a new 4th generation synchrotron radiation facility named MAX IV. MAX IV, through its high brilliance, will allow experiments probing structural and physical phenomena at nanometer scale spatially and the evolution of fast dynamic processes at femtosecond scale temporally. Thus, fundamental insights will be obtained to the benefit of a wide range of scientific disciplines. A panel of international experts has reviewed the scientific case for a MAX IV facility and the result of their evaluation is presented.