There are provided a negative example availability deciding apparatus, a negative example availability deciding method, and a program that enable reuse of training data. A positive example evaluation training section generates a positive example evaluation classifier trained with target data as a positive example. A negative example evaluation training section generates a negative example evaluation classifier trained with target data as a negative example. An availability deciding section determines the classification accuracy of the positive example evaluation classifier and the classification accuracy of the negative example evaluation classifier by using evaluation data. The availability deciding section decides, on the basis of the classification accuracy of the positive example evaluation classifier and the classification accuracy of the negative example evaluation classifier, whether or not to use target data as negative example training data for training another classifier.