a thermoelectric generator apparatus of a vehicle may include a high temperature member , through which exhaust gas passes , a low temperature member , which maintains a temperature lower than a temperature of the high temperature member , and which includes a first coolant pipe holder supporting one of coolant pipes , a heat transfer plate which extends from the first pipe holder and may be located opposite to a corresponding high - temperature member , and a second coolant pipe holder formed on the other side of the heat transfer plate and supporting another of the coolant pipes , and a thermoelectric module disposed between the high temperature member and the low temperature member .