In this study, a solar simulator with a size of 140x250 cm was established to test the solar collectors in the laboratory. Inside of the simulator, 46 pieces of 400 W and 4 pieces of 1000 W halogen lamps were used. The lamps were divided into four groups and their light intensities were adjusted with dimmers. The simulator provided an average intensity of 1080 W/m2 radiation from the 100x200 cm central area. Greenhouse shading material was used on the simulator and the average radiation value was reduced to 896 W/m2. A flat plate solar collector was tested with the prepared simulator. The tests were carried out at 25, 40, 60 and 80 oC constant fluid input temperatures and a standard flow rate of 0.02 kg/s m2. The efficiency of the tested collector was calculated as 72-48% of the working temperature range and the pressure drop of the collector was measured 19.4 pascal. Independently from the variable environmental conditions, flat plate or U-pipe vacuum tube solar collectors could be tested and their efficiency curves could be generated with the designed and established simulator.