A device (10) for analyzing a circuit (14) includes at least one element
(22) for observing light emitted by at least one localized observation
zone of the circuit resulting from the electric current flowing in the
zone; elements (26) for exciting the circuit. The circuit exciting
elements include a laser source (26) and elements (30) for applying a
laser beam generated by the source on the observation zone (22). The
device includes members (M1, M2) for protecting the observation zone (22)
against the incident and reflected laser beams.