The KLL Auger spectrum of chlorine in CCl4 has been investigated with an electrostatic energy analyzer. The ionization in the K shell of chlorine was caused by electron impact. Absolute energies and relative intensities of transitions KL1L1(1S, KL1L2,3(1P), KL1L2,3(3P) and KL2,3L2,3(1D) have been determined. Via the width of the K level of chlorine also experimental values of absolute transition probabilities have been calculated. While the relative intensities deviate strongly from theoretical values, the absolute transition probabilities agree better with theoretical values, especially with those calculated by Rubenstein. - In an appendix the natural line widths of the KLL components of argon have been calculated theoretically. © 1969 Springer-Verlag.