A circuit board testing apparatus for testing continuity and/or
short-circuit of wirings formed on a circuit board, includes an
electromagnetic wave irradiator which irradiates first terminals of the
wirings with an electromagnetic wave so that electrons are discharged
from the first terminals by photoelectric effect. Discharged electrons
are trapped by an electrode which is electrically biased to have a higher
potential than that of the second terminals of the wirings, thereby
causing an electric current to flow through the wirings via the
electrode. Existence of open-circuit and/or short-circuit of the wirings
is judged based on the current flowing the wirings.