A support pin arrangement determination assisting apparatus including a display unit which displays an image including a board image, the board image indicating a shape and an arrangement of a component on the board, a position input unit through which an arrangement position of the support pin is input, a display processing unit which causes the display unit to display a figure to be superimposed on the board image, the figure corresponding to the support pin of which the arrangement position is input, a storage unit which stores three-dimensional shape data of an electronic component and three-dimensional shape data of the support pin, an interference judging unit which judges whether or not one or some of the support pins of which arrangement positions input interfere an already mounted component, and an alarm unit which announces occurrence of interference if the interference judging unit judges the occurrence of interference.