The invention provides a machine learning apparatus and method, life prediction apparatus and a motor driving apparatus. The machine learning apparatus that learns predicted life of a power device of a motor driving apparatus converting DC power into AC power by a switching operation of the power device to supply the AC power to an AC motor includes: a state observation unit that observes a state variable constituted by data regarding the number of times of switching of the power device, data regarding junction temperature of the power device, and data regarding presence or absence of a failure of the power device; and a learning unit that learns the predicted life of the power device in accordance with a training data set defined by the state variable.