Erg Chech 002 (EC 002) is an andesitic meteorite, which is the oldest lava in the Solar System as determined by the 26 Al-26 Mg relative chronometer. Here, we present high precision Ca isotope data for the bulk rock and mineral separates of EC 002, and for the first time, obtain a 40 K-40 Ca isochron by using the Nu Sapphire, a collision cell equipped MC-ICP-MS instrument. The mineral separates yield a 40 K-40 Ca age of 4545 ± 78 Ma with an initial 40 Ca/ 44 Ca = 47.16065 ± 0.00049 (ε 40 Ca SRM 915a = −0.33 ± 0.10). The age is identical with those obtained from other long lived isotopic systematics but more precise, and it is consistent with the short lived 26 Al-26 Mg age. The δ 44/40 Ca of EC 002 is 0.87 ± 0.05 ‰ suggesting that EC 002 might represent a differentiated melt from an ordinary chondritic parent body. The extremely old age of EC 002, along with the similar ε 40 Ca values among most meteorites, suggests that the 40 Ca was homogeneously distributed within early formed planetesimals and the ε 40 Ca value of EC 002 could represent the average of initial ε 40 Ca of the Solar System.