There is provided a circuit design supporting device, a circuit board design supporting system, a circuit board design supporting server, a circuit board design supporting client, a circuit design supporting method, and a program for realizing the device for designing a layout of main components such as LSI, etc. on a circuit board such as a printed circuit board wherein unnecessary electromagnetic radiation is suppressed. The circuit design supporting device comprises a noise generating level adding means and a component locating means. The noise generating level adding means adds noise generating level information to a component to be located on a printed circuit board. The component locating means includes a component position detecting section, a voltage distribution detecting section, a noise generating level comparing section, and an error informing section. The component position detecting section detects a position of the component moved on the printed circuit board. The voltage distribution detecting section detects a voltage level on the printed circuit board in the detected position of the component. The noise generating level comparing section compares the detected voltage level with the noise generating level added to the component. The error informing section informs a user of an error when the voltage level on the printed circuit board is equal to or larger than the noise generating level as a result of the comparison.