PROBLEM TO BE SOLVED: To provide a cardiac disease diagnostic apparatus capable of determining whether a cardiac disease is present or not, on the basis of cardiac sound data.SOLUTION: A cardiac disease diagnostic apparatus 10 comprises: an input signal processor 12 which has an electric signal based on the cardiac sound of a living body inputted thereto, performs predetermined signal processing, and outputs cardiac sound data and a cardiac sound analyzer 13 which calculates a first interval power spector by frequency transformation of cardiac sound data of a first interval, calculates a second interval power spector by frequency transformation of cardiac sound data of a second interval, and diagnoses the presence or absence of a cardiac disease in the living body, on the basis of the difference between the first interval power spector and the second interval power spector.
