We have been developing a new analytical transmission electron microscope (TEM), called a coincidence TEM, which in principle enables elemental mapping images to be observed at a high signal-to-noise (S/N) ratio under very low dose radiation conditions. In this paper, we report the development of a coincidence TEM with a digital waveform measuring system for obtaining a coincidence elemental mapping image. In this system, analog signals detected by a Si(Li) detector and a multianode, position-sensitive photomultiplier (PSPM) are continuously converted into 12-bit digital waveform data at a rate of 100 MHz, and transferred to a PC. From the transferred digital waveform data, information on X-ray photon energy, electron incident position, and detection times of both X rays and electrons are calculated by digital waveform measurement, which lead to the observation of a successful coincidence elemental mapping image. Copyright © 2005 John Wiley & Sons, Ltd.