Geometrical design of the spiral c1ystal selector can ajj (xt crystal orientation in the final single crystal structure. To achieve a better understanding of conditions associated with the onset of crystal orientation in a spiral crystal selector, temperature field was investigated using three-dimensional finite element method during the process. D!fferent geometries of spiral crystal selector were used to produce Al- 3 wt. % Cu alloy single crystal using a Bridgman type furnace. The Crystal orientation of the samples was determined using electron bachcattered d(fftaction (EBSD) and optical microscopy. Analysing the temperature field in the c1ystal selector revealed thai, the orientation of growing dendrites against liquidus isotherm in the spiral selector was the reason for crystal misorientation which differs in various selector geometries. Increasing the take-off angle from 35o up to 45° increases the misorientation with respect to<001> direction. Further increase of take-off angle greater than 45° will decrease the crystal misorientation again and the ejjiciency of the selector to produce a single grain is decreased.