We have studied the photoionization of the 3p electron of Ca in the vicinity of its ionization threshold by means of both an angular correlation measurement between the 3p photoelectron and the M₃N₁N₁ Auger electron, and conventional angular distribution measurements for both the 3p photoelectron and the M₃N₁N₁ Auger electron. We have carried out `random phase approximation with exchange' calculations for the Ca 3p photoionization process, and the results are in good agreement with the amplitudes and phase differences extracted from the experimental data.