An energy treatment instrument includes: an insertion section in which. a longitudinal axis is defined, a probe, an output section, and a detector. The probe is provided on a distal side along the longitudinal axis of the insertion section and is configured to be pierced into a biological tissue. The output section is provided on the probe and is configured to output energy to an outside of the probe when supplied with energy. The detector is configured to recognize presence of an organ which is located farther than an end portion of the probe, when the probe is pierced into the biological tissue.
