A system construction supporting tool that supports construction of a programmable controller system, the system construction supporting tool including: a product-specification storage unit that stores therein information related to product specifications of units to be used as elements for constructing the programmable controller system； an arranged-unit-information storage unit that stores therein information related to arrangements of units already arranged in an edition operation on a display screen； a unit-list-display control unit that extracts arrangeable units based on the information stored in the arranged-unit-information storage unit and the information stored in the product-specification storage unit； and a unit-list display unit that displays a list of the units extracted by the unit-list-display control unit on the display screen.
