An integrated circuit internal signal monitoring apparatus comprises an integrated circuit. The integrated circuit comprises a signal change information generating section for detecting changes in a plurality of internal signals to be monitored in a circuit block, and in response to a level of at least one of the plurality of internal signals changing sequentially generating flags indicating the internal signal whose level has been changed, the post-change level, and that the levels of other internal signals have not been changed; a storage section for sequentially storing the flags and a trigger generating section for generating a write stop trigger signal for stopping a write operation of the flags to the storage section The integrated circuit internal signal monitoring apparatus further comprises an internal signal waveform reproduction section for reading the flags from the storage section after the generation of the write stop trigger signal.