An apparatus for detecting an epilepsy seizure, includes: a graph generating unit configured to generate an orthogonal graph where values of heart beat intervals are sequentially plotted while a heart beat interval at an arbitrary timing is set as a first coordinate and a next heart beat interval is set as a second coordinate; and a seizure detecting unit configured to detect the epilepsy seizure based on: a change of a distribution of a group of the plotted values in a first direction perpendicular to a straight line passing an origin and a point where the first and second coordinates are equal to each other; and a change of a distribution of the group of the plotted values in a second direction parallel to the straight line.