Provided is a boundary search test support device (100) to make it possible to detect boundary points at which output values change in a program created by machine learning more efficiently. The boundary search test support device (100) includes: a storage device that holds a plurality of input vectors (1111); and an arithmetic device that executes a test by sequentially inputting the input vectors to a program generated by a neural network and acquiring output vectors (1141) which are test results, respectively generates, in a coordinate system which takes each of a predetermined plurality of elements among elements constituting the output vectors as a coordinate axis, a straight line in which the plurality of elements has a same value and a hyperplane in which a sum of values of the plurality of elements is taken as a predetermined value, and arranges a most antagonistic point and boundary vectors whose values of the elements rank higher than or equal to a predetermined ranking among the output vectors in the coordinate system, and outputs the coordinate system together with input vectors (1111) corresponding to the boundary vectors on a predetermined output device.